PC Shareware 1996 December/PC_Shareware-1996-12.iso/windows/spectrum/docs/spec_3_0.faq

Text File | 1996-06-11 | 143.0 KB | 3,009 lines

                             comp.sys.sinclair
                          Sinclair ZX Spectrum FAQ
                            v3.02 (June 11 1995)

                         Maintained by Damien Burke
                   email:  [e-mail]
     (until June 14th 1996; check http://www.cs.bham.ac.uk/~dmb/mail.html
                  for a new email address after that date)

   You can find the most recent version of this document at the following
 World-Wide Web (WWW) address: http://www.cs.bham.ac.uk/~dmb/speccy/faq.html

Please send your additions and corrections to the email address above. Much of
this FAQ is the FAQ as previously maintained by Marat Fayzullin, for whom all
old computer fans should give daily thanks and worship ;-)

Copyright note: if you're going to copy this, do it right. OK? I don't care if
you stick this on a CD, print it and make paper aeroplanes from it, whatever -
just don't modify it - tell me if changes need making.

Changes since v3.01:
        1) Emulators list expanded and updated.
        2) Where is...? list expanded and updated.
        3) Some other minor additions/corrections.

Changes since v3.0:
        1) Updated net addresses to give descriptions to/remove all but one
           of the 'No description yet' URLs.
        2) Corrected address of SAM Coupe FAQ.
        3) Expanded description of SPECEMU emulator - thanks Rui.

Changes since v2.9:
        1) Net Addresses list expanded.
        2) Emulators list expanded.
        3) Where Is...? list expanded.
        4) File formats section expanded.
        5) Some information on the 128K hardware added.
        6) More Spectrum models listed.
        7) Various minor additions/modifications.

As I am a university student and about to take a year out to go back to the
real world this may be the last major update of the FAQ for some time. My
university account will become defunct some time around September 1996, and I
am unlikely to be able to read any mail after June 14th 1996, so email to the
address listed above will probably bounce or remain unanswered. I should have
a new address by September 1996; I will make a link available to the new
address on the following web page: http://www.cs.bham.ac.uk/~dmb/mail.html

******************************************************************************
********************************** CONTENTS **********************************
******************************************************************************

I.   FREQUENTLY ASKED QUESTIONS  - and the answers!

II.  NET ADDRESSES               - ZX-Spectrum-related Net addresses

III. EMULATORS                   - comparison of existing ZX-Spectrum emulators

IV.  WHERE IS...?                - what happened to famous ZX-Spectrum people

V.   FILE FORMATS                - descriptions of emulator file formats
     1. Snapshot files           - memory snapshot file formats
       a) .SLT
       b) .SNA (48Kb)
       c) .SNA (128Kb)
       d) .SP
       e) .ZX
       f) .Z80 (all versions)
     2. Tape files               - virtual tape file formats
       a) .TAP ( and .BLK)
     3. Other files              - other emulator file formats
       a) .MDR
       b) .SCR

VI.  TECHNICAL INFORMATION       - info on ZX-Spectrum's hardware
     1. Z80 CPU                  - undocumented opcodes and weird features
        a) CBh opcodes
        b) FDh and DDh opcodes
        c) EDh opcodes
        d) R register
        e) Undocumented flags
        f) IFF1 and IFF2
     2. Hardware                 - ULA and I/O ports
     3. Interface I
        a) Port E7h
        b) Port EFh
     4. The 128K Spectrums
        a) Memory
        b) Keypad
        c) Sound Chip

VII. PINOUTS                     - pinout details for various hardware
     1. ULA
     2. AY-3-8912
     3. Keyboard layout

VIII.ACKNOWLEDGEMENTS            - thanks etc.


******************************************************************************
************************* FREQUENTLY ASKED QUESTIONS *************************
******************************************************************************

1. Just what is this newsgroup for?
   This group's charter (from its original formation in December 1993) is to
   provide a forum for the discussion of the various brainchildren of Sir
   Clive (born Clive Sinclair) and related computers such as the Jupiter Ace,
   TK and TS series', SAM Coupe and Thor, software, peripherals, emulators for
   them, programming them; playing those wonderful games (6031769, anyone?);
   and anything else which interests the Sinclair community. The group is not
   moderated.

   In practice, nost discussion is Spectrum-related, but there's a fair bit of
   SAM Coupe, QL, ZX-81, etc. chat as well. This FAQ only covers the Spectrum,
   other documents being available seperately:
   The QL FAQ at        http://ww.uni-mainz.de/~roklein/ql/
   The SAM Coupe FAQ at http://www.soton.ac.uk/~tsp93ma/Coupe/FAQ.txt

   This FAQ covers technical information, emulator information and resources
   and does not attempt to cover Spectrum games and history. There is a game
   FAQ available - see question 18.

2. Can I post binaries to this group?
   NO! The word 'binaries' does *not* appear in the newsgroup title, and this
   is a subtle indication that posting binaries is going to make you very
   unpopular very quickly. Many people have to pay for net access, and you're
   costing them money if you post binaries, which are substantially larger than
   most posts. You may also cause news providers to stop carrying the group if
   binaries are seen to be posted in it. If you want to distribute something
   Sinclair-related, upload it to an FTP site or put it on a web page and post
   the *address* of the site.

3. Is there a Spectrum emulator for <whatever machine>?
   Probably. See section II, Emulators, below. It is split up by machine type,
   so you should be able to find one you can use. Of course, if you can't get
   one for your machine, you could always write one... ;-)

4. Where can I find <whatever game>?
   The game you're after is probably available somewhere on the net. The
   gopher server at gopher://gopher.nvg.unit.no enables you to search for
   games (web interface to it at http://www.nvg.unit.no/spectrum/search.html),
   but an even better way to search is to use Hynek Med's snapsearch engine,
   located on the web at http://drson.vse.cz/snapsearch.

   Several CDs full of games can be had:-

   Speccy Sensations II: Warm Silence Software at:
   http://www.comlab.ox.ac.uk/oucl/users/robin.watts/wss/index.html

   Emulator Heaven:
   Phone Mike Mee in the UK on [phone] after 6pm or write to
   "Anncott", Hylas Lane, Rhuddlan, Clwyd, LL18 5AG, UK or
   phone 'TortyFoo' also in the UK on [phone] (7pm-10pm Weekdays/
   10am-10pm Weekends) or email:
   [e-mail]

   Bear in mind that these CDs contain a large amount of copyrighted software
   so they are technically illegal!

   If none of those turn up the game you're after, try asking on the
   newsgroup, or (shock) going to a second-hand shop and digging around in
   their boxes of old tapes.

5. Is it legal to use ZX-Spectrum ROM images?
   Yes, it is. Amstrad, who own the copyright for the ROMs, allow free
   distribution of ROMs for emulation purposes, although they often apply
   stipulations such as not charging money for software that includes these
   ROMs. They also allow free distribution of electronic versions of Spectrum
   hardware manuals.

6. Is it legal to use snapshots (i.e. games etc.)?
   Formally, using snapshotted game without actually owning a copy of it on a
   tape is a *copyright violation*. Nevertheless, ZX-Spectrum games are not
   being sold any more and using snapshots doesn't harm copyright holders
   much, if you don't make profit from it and don't distribute snapshots on a
   large scale. Some companies definitely do not like to have their games
   distributed (e.g. Ultimate/Rare), whereas others have given explicit
   permission (e.g. Vortex). A list of such companies/individuals is at
   http://www.cs.bham.ac.uk/~dmb/speccy/permits.html.

7. I have the game I was after, but in a format my emulator can't load. How
   do I convert snapshots between various formats?
   Most snapshots can be converted into one another using SPConv program
   by Henk de Groot [[e-mail]] and myself. An MSDOS version of
   this program is supplied with the JPP emulator (source included), but is a
   rather old version. A more up to date version (v1.10) is available from the
   NVG FTP site: ftp://ftp.nvg.unit.no/pub/sinclair/utils/generic/spcnv110.zip
   SPCONV converts files between following formats: .SIT,.SNX,.SNA,.Z80,
   .PRG,.SP and RAW.
   Also, the registered version of Z80 contains a converter program, and there
   is a program called Butcher, written by Marat Fayzullin (available at the
   NVG FTP site) that can split .ZX (or .SPC) files (used by the "Polish"
   emulator) into a series of .header/.bytes files for use with the Spectrum
   v1.7 emulator on the Amiga.

8. I'm trying to convert a .Z80 file into .SNA format using SPConv and it
   doesn't work. Why?
   You are probably using SPCONV v1.05 which came with JPP distribution.
   It has problems converting .Z80 files created by Z80 v2.01+. Get SPConv
   v1.10 (URL listed in question 7 above). It works.
   SPConv cannot currently handle 128Kb snapshots, but hopefully the next
   version will.

9. I've got a snapshot that won't load into Z80 - it just gives an error
   message saying 'plusdrom.bin not found' and exits to DOS. How can I get it
   to work?
   The snapshot was saved by someone with a registered copy including +D
   emulation, in +D mode. The game doesn't actually *need* the +D ROM, so you
   can use DEMGT: ftp://ftp.nvg.unit.no/pub/sinclair/utils/generci/demgt.zip
   to modify the snapshot so it isn't in +D mode.

10.What is the difference between the various ROM-files available for use
   with Spectrum emulators?
   SPECTRUM.ROM - Spectrum ROM, exactly the same as in the original
                  Spectrum.
   GROOT.ROM    - Same ROM, but with lots of bug fixes and extensions by Henk
                  de Groot [[e-mail]]. List of changes follows:
                  o Bug fixes as mentioned in "The complete Spectrum Rom
                    Disassembly" by Dr Ian Logan and Dr Frank O'Hara.
                  o Support for EPSON printer via an Z80-PIO chip and
                    Centronics connection.
                  o Monitor support: start up with black screen and white
                    characters.
                  o Lightpen support: Lightpen routine for DK'Tronics
                    lightpen is built in.
   TK95.ROM     - ROM from a Brazilian Spectrum clone called Micro Digital
                  TK95.
   IMC.ROM      - Ian Collier's modified ROM. See the documentation that comes
                  with xz80.
   UNICORN.ROM  - ROM used by Mikro-Gen's Shadow Of The Unicorn cartridge
                  game.

11.Where can I get Microdrive cartridges?
   Microdrive cartridges (as well as complete Microdrive kits) can be
   obtained from:

   W.N. Richardson & Co.
   6 Ravensmead
   Chiltern Hill
   Chalfont St Peter,
   Bucks, SL9 0NB
   United Kingdom

   PHONE/FAX [phone]

12.How do I fix my worn out ZX-Spectrum keyboard?
   If the connectors on the PCB have scratched off the silver from the
   ribbon, buy some so-called "conductive paint" which is a suspension
   of fine silver particles. If you let it dry, it conducts. Use a fine
   brush to replace what is scratched off from the ribbons. This paint
   is available from most electronics hobbyist stores (for example, from
   RadioShack in US).

13.What's the address of the "Spectrum Profi Club" in Germany?

   SPC
   c/o Haller
   Ernastr. 33

   D-51069 K"oln
   Germany

14.What are the differences between the different Spectrum models?
   1) 16K    - original model. Rubber keys.
   2) 48K    - (most widespread) original model with RAM extension.
   3) TS2068 - American version from Timex; had an AY-3-8912 sound chip,
               cartridge ports, two joystick ports and an additional 8Kb
               extension ROM with extra BASIC commands to support these
               devices. Silver plastic case and plastic keys.
   4) TC2068 - same as TS2068; sold by a Portuguese arm of Timex away from
               usual Sinclair markets.
   5) TC2048 - another one from Portuguese arm of Timex. Black with grey
               plastic keys. Built in Kempston joystick port, some higher
               resolution screen modes, 64Kb of memory with a paging
               system.
   6) TK90X  - clone of 48K by Micro Digital of Brazil, with a built-in
               joystick interface (Interface II compatible) and two new
               BASIC commands - TRACE, for tracing execution, and UDG for
               editing UDGs. This modified ROM caused some compatibility
               problems.
   7) TK95   - as TK90X, but with a real keyboard (not unlike the C64's) and
               a more compatible ROM. Apparently a TC2048 in disguise.
   8) 48K+   - as 48K, but had "real" keyboard.
   9) 128K   - 128Kb RAM, AY-3-8912 sound chip, keypad, RS232 port and "real"
               keyboard. The last real Sinclair machine.
   10) +2    - 128K with builtin tape deck, new (grey) case and keyboard.
               First Amstrad-produced model.
   11) +3    - 128K with builtin disk drive, new ROMs including a DOS and some
               internal changes on the bus. Back to a black case.
   12) +2A   - +3 with a tape deck instead of disk drive.

15.What peripherals exist?
   This would be a big list, so I'll keep it to what I consider are major
   ones (additions welcome):
   1) Interface 1 - joystick and microdrive interface, network capabilities.
   2) Interface 2 - joystick and cartridge interface.
   3) Microdrive - fast tape storage (requires Interface 1).
   4) ZX Printer - thermal printer (aka silver bog roll burner).
   5) Keypad - extension keypad for the 128K models that offered extra
               editing facilities in 128K BASIC.
   6) Multiface - Romantic Robot's excellent device to stop the Speccy cold,
                  enabling you to save the current state of the machine to
                  tape or disk and enter POKEs.
   7) Joysticks - many interfaces exist; Kempston, AGF/Protek, programmable
                  interfaces (which mapped joystick positions to keypresses),
                  etc. etc.
   8) AMS Mouse - well, a mouse...
   9) BetaDisk - an interface to enable attachment of a 3.5" drive.
   10) Disciple/+D - MGT's interface to enable attachment of a 3.5" drive.
   11) Wafadrive - not unlike a Microdrive.


16.Where is Sinclair Research now? Is Clive on email?
   You could try contacting MENSA; Clive is a member.

   Seamus Waldron [[e-mail]] supplies the following
   from the last Profits/Loss account published by Sinclair Research (on 12th
   October 1995):

      SINCLAIR RESEARCH LTD.
      15/16 Margaret Street
      London
      W1N 7LE
      United Kingdom
      Tel: [phone]
      Fax: [phone]

   Sir Clive Sinclair is still the chairman; no email address is known for
   him (and if you were him and had one, wouldn't you keep it a secret from
   the slavering hordes of Speccy fans?!). Unfortunately the above address is
   already out of date; Sinclair has moved to somewhere near Kings Cross in
   London. More info welcome!

17.What the hell is a Spectrum?
   The best home computer of all time. Came out in 1982 from Sinclair
   Research Ltd., and proceeded to capture the hearts and minds of millions
   of people. Based around a Z80 processor and utilising lots of neat tricks
   to keep the cost down, Clive (now Sir Clive) Sinclair effectively created
   the UK computer industry with his ZX80, ZX81 and ZX Spectrum. If you've
   never used one, get hold of an emulator and try out some of the classic
   games around (e.g. Jetpac) and see what *real* gameplay is about without
   needing 50 Mb of hard disk space and the type of processing power that
   interferes with military radar.

18.Is the Spectrum better than <other machine>?
   Yes. ;-)

19.I have a question not covered here!
   Well, there are other sources of information; in particular, if the
   question is about a particular game, your first stops should be Stephen
   Smith's Speccy Games FAQ and Games Database at:
   http://www.hermetica.com/technologia/sinclair/stevo/gamefaq.html and
   http://www.hermetica.com/technologia/sinclair/stevo/gamedbs/gamedbs.html
   If they don't help, welcome to the group, ask away!


******************************************************************************
******************************* NET ADDRESSES ********************************
******************************************************************************

In between updates of this FAQ, new sites usually appear - I may have linked
to them on my own page at http://www.cs.bham.ac.uk/~dmb/speccy/ (until June
14th 1996) so take a look there if you're after something new. If you find an
address in here that doesn't work any more, please let me know - and let me
know if you find one that isn't listed here too!

This list is ordered by the sites' domain names, so don't feel bad if your
site is listed after one you think isn't as good. If anyone thinks my
description of their site is incorrect or unfair, again, let me know.

================================= FTP Sites: =================================

If you're after games, emulators or anything Spectrum-related, there are a
number of FTP sites worth visiting, and new ones spring up now and again...
bear in mind that many of the sites containing games are very busy, so you're
better off trying at quieter times (e.g. very late at night in the UK), and
don't use a web browser - use a proper FTP client (in which case the name of
the site needs the 'ftp://' bit stripped off).

ftp://akira.uc3m.es
ftp://alba.easynet.co.uk            (part time site - never seen it up myself)
ftp://budda.tixm.tambov.ru/d/incoming/crems/speccy
ftp://drson.vse.cz/pub/sinclair
ftp://fly.cc.etf.hr
ftp://fly.cc.fer.hr/pub2/spectrum
ftp://ftp.dcc.uchile.cl/pub/OS/sinclair
ftp://ftp.demon.co.uk/pub/emulators/spectrum
ftp://ftp.enterprise.net/pub/incoming/speccy
ftp://ftp.enterprise.net/spectrum/
ftp://ftp.funet.fi/pub/misc/if-archive
ftp://ftp.gmd.de/if-archive
ftp://ftp.gui.uva.es/sinclair
ftp://ftp.inf.tu-dresden.de/pub/zxspectrum (and /pub/incoming/zxspectrum)
ftp://ftp.itu.edu.tr/pub/systems/spectrum
ftp://ftp.komkon.com/pub/Spectrum (and /incoming/Spectrum)
ftp://ftp.lanprojekt.cz/pub/sinclair
ftp://ftp.nvg.unit.no/pub/sinclair                    (*THE* Speccy FTP site!)
ftp://ftp.polsl.gliwice.pl/pub/systems/ZXSpectrum
ftp://ftp.sun.ac.za/pub/misc/sinclair (and /pub/msdos/zx)
ftp://ftp.zx-museum.org.ru
ftp://maya.dei.unipd.it/pub/sinclair_QL/spectrum
ftp://members.aol.com/zxspectrum/snaps/
ftp://oak.oakland.edu/pub/msdos/emulators
ftp://phantom.riviera.pw.edu.pl/pub/speccy              (kept by Hacker Chris)
ftp://rcs1.urz.tu-dresden.de/pub/soft/zxspectrum
ftp://spodbox.ehche.ac.uk/pub/users/majik
ftp://tardis.soc.staffs.ac.uk/pub/sinclair
ftp://uhura.ijs.si/pub/zx                              (used to be ftp.ijs.si)
ftp://virgo.inesc.pt/pub/games
ftp://wuarchive.wustl.edu/systems/sinclair
ftp://www.il.ft.hse.nl/pub/sinclair/

================================= Web Sites: =================================

Web sites abound, and new ones appear all the time... try web searches for
'Sinclair Spectrum', 'ZX Spectrum', 'speccy', etc.

===================== Web Sites with Reference Material: =====================

http://www.csv.warwick.ac.uk/~mauqx/sinclair/
Sinclair Index - links and hardware manuals, e.g. Interface 1, Multiface 128
manuals.

http://www.mono.org/~ritchie/speccy/speccy.html
Sinclair Spectrum Home Pages - snapshots and technical articles, and letters
from Your Sinclair!

http://www.nvg.unit.no/spectrum
Spectrum Forever! - THE Spectrum site! A bit disorganised and rather out of
date now, but still a good collection of stuff.

http://spodbox.linux.org.uk/~majik/sinclair/
Sinclair Microcomputer Museum - (aka Sinclair Section).

http://www-users.informatik.rwth-aachen.de/~afw/sincfo0.html
Sinclair ZX Spectrum Forum - primarily a BASIC reference

===================== Web Sites with Games (Snapshots): ======================

http://www.accessone.com/~mcoward/
M. Coward's SpecNet Online; some games on a nicely presented site.

http://alba.easynet.co.uk
John Dow's part-time page - supposedly up at 10-12PM UK time at weekends; I've
never managed to get a response at any time though.

http://homepages.enterprise.net/glyn.harper/spectrum.html
Glyn Harper's ZX Spectrum Emulator page - basically just links to his FTP
site, with around 16Mb of games.

http://ireland.iol.ie/~sjones
Steve Jones' Sinclair Spectrum Page - has a snapshots requests page, though
hasn't been updated since it started from what I can see - apparently due to
worries about copyright violation.

http://lia01.unizar.es/curro/spectrum.htm
Francisco Cotrina's Spectrum page - with details of his snapshots mail server
and some emulators to download.

http://members.aol.com/zxspectrum/speccy.html
Harvey Lodder's "Most Wanted" snapshots request page.

http://osiris.sund.ac.uk/~ca4aba/snaps.html
Andrew Barker's Spectrum Snapshots - yet another requests page, the most
active one.

http://relcom.eu.net/zx/
Aleksandr Babaylov's ZX Spectrum Software Museum - a large collection of
snapshots and tapes; a lot of games here, but it can be a slow site.

http://sable.ox.ac.uk/~sjoh0132/
John Elliott's Home Page - the home of Jet Set Willy 128K, and some useful
icons for Sinclair pages (as used on my page).

http://spodbox.linux.org.uk/~blood/
Blood's Crap Speccy Page - home of the comp.sys.sinclair crap games
compilation and the Manic Miner editor.

http://www.acropolis.gr/~icarus/spectrum.html
Theo Devil's Spectrum page - has copies of his demos and games there, plus
more... you may have heard of Theo as the guy behind Hellenic Software, he
had a few things published on Crash/YS cover tapes.

http://www.cs.ucl.ac.uk/students/zcacbb1/spectrum/speccy.html
Ben Baylis' Spectrum Stuff - including the beginning of a point and click
snapshots list (using the akira FTP site), a requested snapshots page and
YS Smash Tips!

http://www-dse.doc.ic.ac.uk/~np2/spectrum/index.html
Execute Spectrum Programs via The Web! - not really practical, but worth a
look.

http://www.io.org/~diehl/speccy.html
Eric March's Speccy! - including what was a great requested snapshots page,
but it hasn't been updated since August 1995. Should hopefully be back on form
shortly, as Eric will be updating the site with more snapshots and other
stuff 'soon'.

http://www.rtc-carlow.ie/student/obrienk/spectrum.html
Karl O'Brien's Sinclair Spectrum 48K Heaven - has a few games and a copy of
Z80 on his page.

=============== Web Sites with Game Hints/Cheats/Information: ================

http://carlton.innotts.co.uk/~silthas/spectrum.html
Sinclair Spectrum Hall of Fame - screenshots of classic games.

http://orca.ucd.ie/~conormc/spectrum/zxspectrum.html
Conor McCarthy's ZX Spectrum page - home of the Miner Willy Museum (tours of
Manic Miner etc.), and more broken links than you can shake a stick at - all
very much under construction.

http://www-dept.cs.ucl.ac.uk/students/zcacbb1/spectrum/smashtips/
YS Smash Tips - courtesy of Ben Baylis. Lots of tips and cheats.

http://www.doggysoft.co.uk/chzxp.html
Cheats Prosper - Multiface POKEs - an impressive list of cheats here.

http://www.ftech.net/~floodnet/spectrum/spectrum.htm
Glenn Flood's Spectrum/ZX-81 Cassette Inlay Artwork Page - Glenn did artwork
for some QuikSilva games.

http://www.gatewest.net/~cpb/lom.html
The Moon Palace - a home page for the Lords of Midnight saga.

http://www.hermetica.com/technologia/sinclair/stevo/index.html
Stephen Smith's Master Speccy page- lots of stuff including the Spectrum games
database and games FAQ. A must see!

http://www.soton.ac.uk/~rjc394/
The YS Tip Shop Tiptionary- courtesy of Robert Cooper. Decidedly incomplete;
not updated since it was first put up.

http://www.wintermute.co.uk/users/gargamel/ultimate.html
Gargamel's Ultimate Play The Game Loading Screens.

================== Web Sites of Emulator/Utility Authors: ====================

http://diana40.paisley.ac.uk:80/~com40014/
James McKay's PC Games Haters Page - home of x128, the DOS and UNIX Speccy
emulator. May disappear after June 1996.

http://fly.cc.fer.hr/~arsen/tapefix/
TapeFix - a program to make your old Speccy tapes readable once more.

http://julia.gns.getronics.nl/~mheide/spectrum.html
Martijn van der Heide's Spectrum Games Database - a PC program to catalog
your snapshot and tape collection and launch JPP or Z80 to run a particular
snapshot or tape. A very well done program, and it's free!

http://web.jet.es/~tpomar/
Toni Pomar's ZXAM homepage - home of ZXAM, oddly enough.

http://www.comlab.ox.ac.uk/oucl/users/ian.collier/Spectrum/index.html
Ian Collier's xz80 homepage - home of xz80, believe it or not.

http://www.comlab.ox.ac.uk/oucl/users/robin.watts/wss/index.html
Warm Silence Software - the producers of Z80Em.

http://www.csd.uu.se/~richardc/home.shtml
Richard Carlsson's home page - author of Speccylator, a Speccy emulator for
the Amiga. You'll find a mention of it right at the bottom of his page.

http://www.doggysoft.co.uk/
DoggySoft have written several Acorn ARM Spectrum-related utilities.

http://www.freeflight.com/fms/
Marat Fayzullin's home page - author of emulators for the MSX, NES,
Colecovision, Game Boy etc. and at least one Spectrum-related utility
(Butcher).

http://www.ugr.es/~pedrom/sinclair.htm
Pedro Salaz's Sinclair home page - home of the Sinclair v2.00 emulator.

============================= Web Search Engines: ============================

http://altavista.digital.com/
Alta Vista - Digital's rather neat search engine. Very powerful, for instance
it can do searches for pages linked to a specific page as well as search in
USENET news articles and web pages.

http://drson.vse.cz/snapsearch/
Hynek Med's Spectrum related files search - searches over several FTP/WWW
sites to match the filename you give it. Probably the most useful search
engine if you're after a particular game.

http://ftpsearch.unit.no/ftpsearch/
FTP Search - will search for any file on the FTP sites it indexes; can also
be used to find Spectrum files of course! Much like Archie, but nicer.

http://www.infoseek.com/
InfoSeek Guide - another generic web search engine, but as always, these are
just as useful for finding Speccy stuff as finding anything else.

http://www.nvg.unit.no/spectrum/search.html
An interface to the gopher search engine at NVG. Unlike snapsearch, this one
searches on company and game names as well as the filename; but it doesn't
have as good an index, so snapsearch often gives better results.

http://www.yahoo.com/Computers/Hardware/Platforms/Sinclair
Yahoo's Sinclair page - a few links, some out of date.

============================ Magazines On The Web: ===========================

http://jumper.mcc.ac.uk/~simonc/ys
Your Sinclair - parts of some of the later issues up on the web courtesy of
Simon Cooke, YS's tech tips editor for those issues.

http://www.cs.bham.ac.uk/~dmb/speccy/emulate/
Barry Plewa's Emulate! - has games, technical stuff, reviews, chart listings,
and much more. The HTML version of the magazine is at this site, but plain
text versions and ZIPped up copies of the HTML version are also available,
e.g. from
ftp://ftp.demon.co.uk/pub/emulators/spectrum/magazines/emulate/ and
ftp://ftp.nvg.unit.no/pub/sinclair/snaps/discmag/emulate/

============================== Other Web Pages: ==============================

http://hal.cling.gu.se/~cl0polau/zx.html
Sinclair ZX Spectrum - a bit empty, this page.

http://members.aol.com/jozxyqk/specmain.htm
Spectrum Appreciation Society. Windows version of Advanced Lawnmower Simulator
and some sound samples.

http://paul.rutgers.edu/~savoiu/spectrum/
Sinclair ZX Spectrum Switchboard - just links.

http://sunsite.dcc.uchile.cl/sinclair/
Sinclair Pages - all in Spanish and all very unfinished looking.

http://stunix.matsim.udmurtia.su/~alt
Aleksey Titov's [[e-mail]] site; apparently to be up
soon, but hasn't been every time I've tried.

http://tachyon.mono.org/~sinclair/
Sinclair Scene - Monochrome BBS's Speccy web page; instructions on how to
access Monochrome and see the actual Sinclair section within. Monochrome is
a telnet-based BBS.

http://www.8bit.com/
8 Bit Universe. Under construction when I looked; but there will be a
Spectrum area. Currently there are two German Spectrum adverts.

http://www.afn.org/~afn09039/sinclair.html
Andy's Sinclair Spectrum Page - just a mention of Ant Attack and Speccy
repair, more to come apparently...

http://www.aston.ac.uk/~goringgn/
No description yet.

http://www.dur.ac.uk/~d44abw/spectrum.html
Spectrum Page - just links.

http://www.earth.ox.ac.uk:80/~steve/Spectrum/index.html
Sinclair ZX Spectrum Flyer - some old advertising bumph.

http://www-ia.di.fct.unl.pt/~vjr/Spectrum.html
Vitor Rocio's Spectrum stuff - just links, though he promises more in the
future.

http://www.il.ft.hse.nl/~ben/sinclair/sinclair.html
Sinclair Page - links and info on SAM Coupe and Dutch QL user group (in
Dutch!).

http://www.nvg.unit.no/spectrum/jmg7/
John Garner's Spectrum PD/User Groups page.

http://www.ozemail.com.au/~martinf/
Martin Fowler's Australian Retro Computing has links to all sorts of old
computer stuff, with the bonus of local copies of emulators etc. so
Australians don't have to wait ages for the download.

http://sol.soc.staffs.ac.uk/cm5bcpmh/sinclair/index.html
Patrick Hill's Sinclair Zone. Some stuff on the C5.

http://www.wam.umd.edu/~audley/english/speccy.html
Damian Audley's Speccy Page - mostly links for Mac emulators etc.

http://zipi.fi.upm.es/~a920142/spectrum.html
Eduardo Garcφa Gallego's Spectrum page - just links.

================================ News Group: =================================

Well, I'd guess you know about the newsgroup if you're reading this, but
maybe not, so...

news:comp.sys.sinclair
(or just comp.sys.sinclair if you're not using a web browser)

Mailing list (the mailing list is a feed from the newsgroup):
Send mail to [e-mail] with the following in the BODY of the message (not
the subject as previously stated in this FAQ - sorry!):

subscribe sincnews [e-mail]

Don't put anything else in the body of the message.

==================================== IRC: ====================================

The channels #spectrum and #sinclair are now officially registered with
DALnet; here are some DALnet servers:

liberator.dal.net (UK) (port 7000)
irc.dal.net (USA) (port 6667)
igc.dal.net (USA) (port 6667)

If you are interested, please email Theo Develegas [[e-mail] -
his IRC nick is _Wind_], so that he can fix some online meetings. He also
plans to have an IRC section on his home page (see above).

============================== Other Resources: ==============================

gopher://gopher.nvg.unit.no
A Spectrum-related files search engine. Searches on company and game names as
well as file names.

Venture BBS in Finland: [phone]
The Bus Stop BBS in England: [phone] (go to area 34)

There is also Alchemist News, a tape-based Spectrum magazine. Past issues can
be found on NVG: ftp://ftp.nvg.unit.no/pub/sinclair/snaps/discmag/alchnews/
and you are best off reading one of them for more information.

******************************************************************************
********************************** EMULATORS *********************************
******************************************************************************

Authors, where known, are in (brackets) after the name of the emulator. Email
addresses are in [square brackets]. PLEASE don't bother these guys asking for
an emulator; there are plenty of places to get the emulators from, and I now
list example addresses.

The features of each emulator are listed in the following set order:

a) Emulation: 48/128/+2/+3/Multiface/Disciple/Interface 1/etc.
b) Loadable formats - e.g. .SNA, .Z80 etc.
c) Saveable formats.
d) Real tape loading - type of support offered.
e) Requirements - video, processor etc.
f) Speed.
g) Status: freeware/shareware/commercial/etc.
h) Good points.
i) Bad points.
j) Other comments.
k) Site available from. Please note that these are not the *only* places to
   get the emulator from; there are many other sites, but the directories
   may be different. Try a WWW/FTP search for the name of the archive file
   if the site listed is too slow for you.

Emulators for MS-DOS PCs:
-------------------------

1. Elwro 800-3 Jr v1.0 (Piotr Schmidt & Piotr Wolter)

   a) Emulates an Elwro - not 100% compatible with ZX Spectrum (the real
      Elwro had problems with JetPac while other games were ok) - with
      two disk drives accessed via * commands (e.g. SAVE * "file") with
      capacity of about 700kB. These are physically files.
   b) Loads files from disk. Snapshots/tape files?
   c) Saves files to disk. Snapshots/tape files?
   d) Real tape support?
   e) Requires Hercules, CGA or EGA.
   f) Speed?
   g) Commercial only.
   h) Capable of running CP/M. Changeable interrupt frequency (45, 50,
      65, 70 Hz). Comes with utility to read the real Elwro Junior disks on
      PC.
   i) Bad points?
   j) All system messages are in Polish.
   k) Available from?

2. JPP (Arnt Gulbrandsen [[e-mail]])

   a) Emulates 48K Spectrum, Kempston joystick (using PC joystick).
   b) Loads .SNA snapshots and from sampled tapes (.VOC).
   c) Saves .SNA snapshots.
   d) Tape support (read-only) via sampled sound files (.VOC).
   e) Requires VGA. Real-speed version requires 286 or above.
   f) 386/25MHz or faster is needed for the best perfomance. 486/25MHz
      or 386/44MHz is needed for good sound emulation.
   g) Freeware.
   h) Includes program for reading and converting snapshots from MGT disks.
      Also includes a very old version of SPConv.
   i) Screws up system screen mode on quit. Restore with MODE CO80 command.
      R register imperfectly emulated. No rainbowing.
   j) Two versions supplied; one for slower machines, and one (PJPP) for
      faster machines; PJPP has better emulation and emulates the FLASH
      attribute and the border. No longer being updated.
   k) Available from ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/jpp.zip
      http://www.nvg.unit.no/spectrum is maintained by the author, but does
      not have any specific mention of JPP.

3. Sinclair v0.99 (previously SPECTRUM in this FAQ) / VGASPEC / SPEC386
                                                                (Pedro Gimeno)
   a) Emulates 48K Spectrum.
   b) Loads .SP snapshots.
   c) Saves .SP snapshots.
   d) Loads from tapes through a wire connected to the parallel port.
   e) Requires VGA, 286. (386 for version 0.99D - SPEC386.EXE)
   f) Matches real Spectrum speed at 386/25MHz.
   g) Shareware.
   h) Good points?
   i) R register and I/O (other than tape) are not emulated.
   j) VGASPEC emulator is an *illegal* prerelease of this emulator.
      All documentation and onscreen messages in Spanish.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/vgaspec.zip
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/span099d.zip

4. Sinclair v2.00 (Pedro M. R. Salaz [[e-mail]])

   a) Emulates 48K Spectrum.
   b) Loads .SIT snapshots and from .BLK tape files.
   c) Saves .SIT snapshots and to .BLK tape files.
   d) Real tape support via a seperate program only supplied with registered
      version.
   e) Requires VGA.
   f) Speed quite good on a 486SX/25.
   g) Shareware; unregistered version has nag screen that renders the built-in
      debugger practically unusable. Registered version comes with utility to
      convert .SP snapshots (from the above similarly named emulator!) to .SIT
      format, can save Spectrum screen to .PCX screens and comes with a
      tape loader program, plus a disk full of games as .BLK files.
   h) Built-in debugger (much like Borland's Turbo Debugger) for stepping
      through, breakpointing, modifying etc. Z80 code (including the ROM).
   i) Speed varies with what the Spectrum program is doing.
   j) Available in both Spanish and English versions. The .BLK file format is
      the same as Z80's .TAP format. I don't think this emulator has any link
      to the other one of the same name.
   k) Available from the author's web site at
      http://www.ugr.es/~pedrom/sinclair.htm as well as
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/sinceng2.zip

5. SP / Polish emulator (Author?)

   a) Emulates 48K Spectrum.
   b) Doesn't load snapshots. Loads from .SPC/.ZX tape files.
   c) Doesn't save snapshots. Saves to .SPC/.ZX tape files.
   d) No real tape support.
   e) Requires CGA or EGA and a ROM file called ROM.SPC - this file is just a
      16Kb ROM dump, identical to the SPECTRUM.ROM file included with JPP and
      xz80.
   f) Speed not known.
   g) Freeware?
   h) Built in MON-like debugger (press F8) for stepping through Z80 code.
   i) No accompanying documentation at all. Colour palette a bit odd.
   j) No other comments.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/polish.lzh

6. The Spectrum Emulator / SPECEM / Irish emulator (Kevin J. Phair)

   a) Emulates 48K Spectrum with Multiface 1, Kempston joystick (with cursor
      keys and Alt).
   b) Loads .PRG snapshots and files from 'tape' - i.e. your hard disk.
   c) Doesn't save snapshots. Saves files to hard disk.
   d) No real tape support.
   e) Requires 16MHZ 286, EGA or better.
   f) Works reasonably fast on 286 and a bit faster than necessary on
      386/486 systems. 386/40MHz or 486/25MHz is needed for good sound
      emulation.
   g) Freeware, but a donation to the author gets you the source code plus
      'various utilities'.
   h) Includes program for loading snapshots from MGT/Datel Plus-D disks.
      Comes with a Z80 disassembler written in BASIC, and a speed testing
      program. Ran at least one snapshot (Scumball) that no other emulator
      could manage (JPP's documentation makes a mention of this one not
      working - Arnt thought it was a bad snapshot).
   i) Imperfect R register emulation. Allows modification of the ROM (though
      it does get refreshed to normal condition whenever loading/saving).
   j) Onscreen display of Z80 registers (can be disabled, but not removed from
      the screen). Attributes can be disabled for faster emulation.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/irish.zip

7. SP_UKV / SP_EMU (Author?)

   a) Emulates 48K/128K Spectrum with TR-DOS (Technology Research Disk
      Operating System for the BetaDisk 3.5" disk drive).
   b) Loads .SNA (both standard 48K and a new 128K version) and 128K .Z80
      snapshots.
   c) Saves .SNA (48/128) and 128K .Z80 snapshots.
   d) Real tape support?
   e) Requires VGA.
   f) Rather slow on a 486SX/25.
   g) Shareware. Registered version has an excellent Turbo Debugger style
      debugger (similar to Sinclair v2.00's one).
   h) Good points?
   i) Bad points?
   j) Usually found as SP_UKV.ARJ along with SP_EMU.ARJ; the latter being a
      cracked version which appears to be enable all the options only
      available if you register it. The help screen is identical to the one on
      the Polish emulator - was that an old version?
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/sp_ukv.arj
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/sp_emu.arj

8. ZX-Spectrum 128K + TR-DOS 1.05 / SP105 (Author?)

   a) Emulates 48K/128K Spectrum with TR-DOS.
   b) Loads?
   c) Saves?
   d) Real tape support?
   e) Requires VGA.
   f) Speed?
   g) Status?
   h) Good points?
   i) Refuses point blank to run in a Windows DOS session. Actually, should
      this be a good point? ;)
   j) All messages and documentation in Russian... if anyone fancies doing a
      translation, I'd be very grateful! Written by somebody from Moscow on
      FidoNet; no email address for them.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/sp105.arj

9. Warajevo v1.2 (Zeljko Juric [[e-mail]] and
                   Samir Ribic [[e-mail]])
   a) Emulates 48K/128K/+2 Spectrum, ZX Printer, Interface 1 (only RS232),
      Kempston joystick (with cursor keys and + or ~ keys as fire or with PC
      joystick or mouse), 128's keypad.
   b) Loads .SNA and .Z80 snapshots and from near-perfect virtual tape (.TAP)
      format - this is not the same as Z80's .TAP format.
   c) Saves .Z80 snapshots and to .TAP tape files.
   d) Supports loading from real tapes only via an RS232 link from a real
      Spectrum.
   e) Requires 286, Hercules, CGA, EGA or VGA.
   f) Around 15% slower than Z80; not noticeable on anything more powerful
      than a 386.
   g) Freeware, though the authors welcome donations, in return for which you
      at least get your name listed in the documentation of the next release.
   h) Better AY-sound through PC speaker than any other PC emulator. Built-in
      debugger, though not as friendly as the ones in Sinclair v2.00 and
      SP_UKV. Can create stand-alone snapshot files that don't need to be
      loaded into an emulator. Comes with suite of utilities built into a
      single program - for converting from various formats, holding a database
      of games, etc. Lots of options.
   i) Colour palette looks a bit odd.
   j) Written under very poor conditions during war in Bosnia. Generally
      considered the second best Speccy emulator on the PC.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/warajevo-spectrum-120.zip

10. WSpecem v1.11 (Rui F. Ribeiro [[e-mail]] until June 1996)
   a) Emulates 48K Spectrum with Kempston joystick.
   b) Loads just about every snapshot and tape format there is, including SLT.
   c) Saves just about every snapshot and tape format there is, but not SLT.
   d) Real tape support provided via an extra program.
   e) Requires MS Windows 3.1, 3.11 or 95, WinG.
   f) Around 25-30% Spectrum speed on a 486SX/25 @ 800x600 res, 64K colour
      Cirrus video card, 8MB machine. Runs at a bit over 100% speed on a P75
      with otherwise identical setup. Note these speeds are for 1x1 scaled
      window with a /3 frame rate. Larger sizes and full frame rate are
      slower.
   g) Freeware - GPL; all the author wants is a postcard.
   h) Resizable window, with quick 1, 2 and 3 times normal size settings as
      well. Quick save/load function for saving a snapshot and reloading it
      without going through a file selector. Drag and drop snapshot loading.
      Source (in C) supplied. Saves Spectrum screen to SCR and PCX files.
   i) Doesn't save SLT snapshots yet. And my machine isn't fast enough :(
   j) The very first Spectrum emulator for MS Windows.
   k) Available from
      http://lia01.unizar.es/curro/wspecem.zip
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/wspv111.zip

11. Z80 v3.03 (Gerton Lunter [[e-mail]])

   a) Emulates 48K/128K Spectrum with Multiface 1/128, cursor, Sinclair and
      Kempston joysticks, AMS Mouse, Disciple disk interface, Interface 1 and
      Microdrives, SamRam (author's own ROM with a basic MON-like debugger).
   b) Loads .SNA and .Z80 snapshots, including level-loader support, and from
      .TAP tape files.
   c) Saves .Z80 snapshots and to .TAP tape files.
   d) Loads from sample tapes (.VOC) and direct from Sound Blaster MIC input,
      or from parallel port using a custom interface (all these only in the
      registered version, and the parallel port interface itself costs extra -
      though a diagram is provided if you want to build your own). Contrary to
      what several people think, this support *does* allow loading of turbo-
      loaders, speedlock games, etc.
   e) Requires Hercules, CGA, EGA or VGA.
   f) Can be up to 200% Spectrum speed on a 486SX/25, depending on emulation
      options chosen.
   g) Shareware. Registered version has real tape support and can be slowed
      down, and comes with several utilities (for converting from various
      formats) and source code (mixture of assembler and C).
   h) Most user-friendly emulator; very good menu-interface and documentation.
      Good high-resolution colour emulation (rainbowing!).
   i) 128K sound can be a bit wobbly.
   j) Usually considered to be the best emulator available for any platform.
      Earlier versions were pretty good but do not compete with version 3.03,
      though version 3.02, which was released on a PC Format cover disk, had
      speed control whereas 3.03 does not unless you register it. However, the
      PC Format version is not distributable - if you have it and didn't buy
      that issue of PC Format, their lawyers may want to talk to you! Version
      3.04 expected soon; it will have, among other updates, support for .SLT
      snapshots. A Windows version is also in development.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/z80-303.zip

12. Z80-TR-DOS 2.02 (modified version of Z80 3.02 by VitaSoft)

   a) As Z80, with addition of TR-DOS emulation.
   b) As Z80.
   c) As Z80.
   d) No real tape support; if you want that, you'll need to register a real
      version of Z80.
   e) As Z80.
   f) As Z80.
   g) An illegal hack.
   h) As Z80. Version 3.02 of Z80 had slightly poorer high resolution colour
      emulation however; and this hack is the same.
   i) As Z80.
   j) This program is an obviously modified copy of Z80 version 3.02 (as
      released on a PC Format cover disk) with Russian documentation. The
      title screen has some cyrillic text on it along with what I presume is
      a phone number (In Russia? Of whoever is behind VitaSoft?).
   k) Not made available at Gerton's request, nor will I reveal the site I got
      it from. No doubt it will soon turn up from somebody else less honest
      than me though...

13. ZX Spectrum-Emulator v1.0s / SPECEMU (Bernd Waschke)

   a) Emulates 48K Spectrum, Kempston joystick (using PC's analogue or digital
      joystick).
   b) Loads .SEM snapshots.
   c) Saves .SEM snapshots.
   d) Real tape support (registered version only) via a Soundblaster card, but
      you have to manually calibrate it with a number.
   e) Requires 386DX/40 and 1Mb of RAM.
   f) About 75% of normal Spectrum speed on a 486SX/25.
   g) Shareware. Some options not present in unregistered version.
   h) POKE facility. Also has what appears to be a Game-Genie/Game Wizard-like
      option to automatically find POKEs (registered version only).
   i) Doesn't emulate flags register properly; in particular, the H flag.
      BRIGHT attribute not emulated.
   j) All documentation and onscreen messages in German. Anyone fancy
      translating it?
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/specemu_1_0s.zip

14. x128 v0.4 (James McKay [[e-mail]] until June 1996)

   a) Emulates 48K/128K Spectrum, Kempston/Sinclair/Cursor joysticks.
   b) Loads .SNA, .Z80 and .SLT snapshots, and from Z80's .TAP tape files.
   c) Saves .Z80 and .SLT snapshots.
   d) No real tape support.
   e) Requires VGA.
   f) About 50% of normal Spectrum speed on a 486SX/25.
   g) Freeware.
   h) Hi-res emulation of screen and left & right border allowing colours
      in an 8x1 block (rainbowing). 128K sound is very good. Now has a
      file selector and much better user interface than previous versions.
   i) Some changeable options require re-compilation.
   j) Also available for UNIX/Linux systems with X Windows (X11).
   k) Available from author's home page (until some time in June 1996) at
      http://diana40.paisley.ac.uk:80/~com40014/ as well as
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/pc/x128v04.zip


Emulators for CBM Amiga:
------------------------

1. KGB v1.3

   a) Emulates 48K Spectrum, cursor joystick (with cursor keys) and Kempston
      joystick (with Amiga joyport 2).
   b) Loads .ZX snapshots.
   c) Saves .ZX snapshots.
   d) Loads/saves from/to real tapes via a sound-digitiser.
   e) Requires monochrome or colour.
   f) Speed not known.
   g) Freeware?
   h) Has a pitch-compensated mode, that transposes the sound two octaves
      up (handy on slow Amigas).
   i) Doesn't multitask. Isn't completely compatible with ZX-Spectrum; several
      games don't work, e.g. Chronos, Starstrike II.
   j) No other comments.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/amiga/kgb-1.3.lha

2. Speccylator v1.0 (Richard Carlsson [[e-mail]])

   a) Emulates 48K Spectrum.
   b) Loads .SNA snapshots, no tape support.
   c) Saves .SNA snapshots, no tape support.
   d) No real tape support.
   e) Requires just any Amiga and around 300Kb of free memory.
   f) 'Faster than most' - except Peter McGavin's Spectrum on a 68000-based
      Amiga.
   g) Freeware.
   h) Fully multitasking, nice graphical interface, better sound than Peter
      McGavin's Spectrum. Can dump Spectrum screen to an IFF ILBM file.
      Preferences can be set globally and for individual snapshots. Better
      Z80 emulation than ZXAM.
   i) No particular bad points, unless you count lack of features - e.g.
      there's no joystick support.
   j) The idea behind the project was to create a Z80 emulation kernel that
      could run on any 68000 machine, i.e. not using any Amiga specifics.
      The Z80 emulator kernel can therefore be used for an emulator on any
      other 68000-based machine, e.g. the Atari ST. Not updated for some time
      due to author being busy with other things, but he will be making some
      updates soon (having seen ZXAM!).
   k) Available from author's homepage:
      http://www.csd.uu.se/~richardc/

3. ZXAM v2.0 (Toni Pomar [[e-mail]])

   a) Emulates 48K Spectrum, Kempston, Sinclair II and Cursor joysticks. Also
      emulates the 128K's AY-8910 sound chip, so 128K-enhanced games that use
      only the sound chip and not the extra RAM often work and give better
      sound.
   b) Loads .SNA and .SP snapshots. Can also apparently load just about any
      format of snapshot via Rexx scripts. Loads tape files from disk.
   c) Saves .SNA (and .SP?) snapshots. Can apparently save just about any
      format of snapshot via Rexx scripts. Saves tape files to disk.
   d) Real tape support via a custom tape interface (diagram and instructions
      to make this are supplied).
   e) Kickstart 2.04 and 68020 or higher required.
   f) Apparently 'impressive' on an A1200.
   g) Shareware.
   h) Runs in a window on Workbench screen, on a separate draggable screen, or
      in exclusive mode. Automatic speed adjustment for fast machines. Can
      save snapshots to a real tape for loading on a real Spectrum. Can load
      PowerPacked snapshots if you have the powerpacker.library in the LIBS:
      drawer.
   i) At least 38 games (including Chronos and Starstrike II) do not work; so
      emulation obviously isn't perfected.
   j) Author is working on fixing problems that cause those games not to work,
      along with a built-in debugger, full 128K emulation and tape loading via
      sound samples. There is a thing called the 'ZX Poke Guide' which is not
      an emulator but instead it's an AmigaGuide by Richard Koerber
      [[e-mail]] full of POKEs (about 677 games). It uses the
      ARexx port of ZXAM to make the pokes and run/stop the emulator from the
      AmigaGuide itself.
   k) Available from author's homepage:
      http://web.jet.es/~tpomar/ (that last slash is very important!) as well
      as the 'misc' directory on AmiNet. The ZX Poke Guide (v2.0) can also be
      found there, e.g.:
      http://ftp.wustl.edu/pub/aminet/misc/emu/ZXPokeGuide20.lha

4. Spectrum v1.7 (Peter McGavin [[e-mail]])

   a) Emulates 48K Spectrum, cursor joystick (with cursor keys) and Kempston
      joystick (with Amiga joyport 2).
   b) Loads .SNA snapshots and tape files from seperate .header and .bytes
      files on Amiga disks.
   c) Saves .SNA snapshots and tape files to seperate .header and .bytes files
      on Amiga disks.
   d) Load/saves Spectrum files from/to tapes through a sound-digitiser.
   e) Toni Pomar says this one is 68000 only and incompatible with Kickstart
      2.0 and up. Comment on speed, below, seems to disagree with this...
   f) Is reasonably fast on 68030/25MHz, but slow on 68000/7.14MHz machines.
      At least 68020/14MHz (A1200) and FAST RAM are recommended. Not as fast
      as ZXAM.
   g) Freeware?
   h) Multitasks.
   i) Colour palette is a bit strange.
   j) Very old, and not supported any more.
   k) Available from
      gopher://micros.hensa.ac.uk:70/11/micros/amiga/dos/t/t042

5. ZX-Spectrum v4.71 (Jeroen Kwast [[e-mail]])
   a) Emulates 48K Spectrum.
   b) Loads?
   c) Saves?
   d) Real tape support?
   e) Requires?
   f) Speed?
   g) Status?
   h) Good points?
   i) Bad points?
   j) No other comments.
   k) Available from 'misc' directory on AmiNet, e.g.:
      ftp://src.doc.ic.ac.uk/pub/aminet/misc/emu/zxspectrum4.71.lha

5. ZX Spectrum Emulator v0.10 (A.Schifano & V.Gervasi)
   a) Emulates 48K Spectrum, presumably, and Kempston joystick.
   b) Loads snapshots (type unknown) and from tape (AmigaDOS files).
   c) Presumably saves snapshots and to AmigaDOS files.
   d) Real tape support via a tape interface.
   e) Requires any Amiga.
   f) Speed? Has three video modes; monochrome, where you choose the overall
      PAPER and INK colour for the screen; colour 1 with limited updates of
      the screen and colour 2 with full updates (slower).
   g) Appears to be a commercial product. The demo does not include tape
      support or snapshot support, and resets after a certain amount of time.
   h) Good points?
   i) Spectrum ROM doesn't come with the emulator; apparently Amstrad denied
      permission (perhaps because this is a commercial product). A hacked
      version of the demo does include it, illegally.
   j) Information here comes from a brief Readme file in a hacked demo version
      of the emulator. More information welcome.
   k) Available from DigiMail in Italy:
      Digimail Srl         Phone: ++39-2-427621
      Via Coronelli 10       Fax: ++39-2-427768
      20146 Milano
      ITALY


Emulators for Atari ST(e)/TT/Falcon:
------------------------------------

1. ZX-SPECTRUM Emulator / Specci v2.07 (Christian Gandler)

   a) Emulates 48K Spectrum, Interface 1 (Microdrives and RS232), Kempston and
      Sinclair joysticks.
   b) Doesn't load snapshots. Loads tape files from seperate files on Atari
      disks.
   c) Doesn't save snapshots. Saves tape files to seperate files on Atari
      disks.
   d) No real tape support.
   e) Requires at 1Mb of memory.
   f) Speed is around 70% (at best) of real Spectrum on plain STs.
   g) Freeware?
   h) Also runs on TTs and Falcons (in ST low/high resolutions).
   i) Bad points?
   j) All documentation in German. There is a poorly-translated version of the
      documentation supplied (taken from a 'Pompey Pirates' disk that had this
      emulator on it) with at least one of the copies on the FTP sites.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/atari/zx_sp207.zip
      gopher://micros.hensa.ac.uk:70/11/micros/atari/tos/o/o096
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/atari/atari-speccy.zip
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/atari/atari-spectrum.zip
      (last two may be earlier versions)

Emulators for Acorn Achimedes:
------------------------------

1. !MZX v1.0 (Graham Willmott)

   a) Emulates 48K Spectrum.
   b) Loads .SNA snapshots.
   c) Saves .SNA snapshots.
   d) No real tape support?
   e) Requirements?
   f) Runs at ~60% normal spectrum speed on an ARM2 machine, and considerably
      faster on other machines - currently there is no speed control available.
   g) Freeware?
   h) Multitasks (can also single task if required).
   i) Doesn't emulate R register correctly, or certain undocumented
      instructions.
   j) No other comments.
   k) Available from
      gopher://micros.hensa.ac.uk:70/11/micros/arch/riscos/b/b166
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/arm/mzx110.spark

2. !Speccy (Karsten Witt)

   a) Emulates 48K Spectrum.
   b) Doesn't load snapshots. Loads tape files from disk in its own file
      format.
   c) Doesn't save snapshots. Saves tape files from disk in its own file
      format.
   d) Comes with application instructions for transferring tape files to/from
      real tapes through the serial port.
   e) Requirements?
   f) Runs at normal Spectrum speed on an ARM2 machine and very fast on an
      ARM3 machine. The speed is adjustable.
   g) Freeware?
   h) Has an enhanced keyboard layout - there are keyboard short cuts to Caps
      Lock, Extended Mode, and also the cursor keys, the keypad, and other
      symbols (commas, colons etc.) can be entered easily.
   i) Doesn't fully implement the R register - however this doesn't affect
      most programs.
   j) At the moment does not load/save in any snapshot formats. Apparently,
      the author is currently working on making it run in the desktop
      (multi-tasking) and allowing loading of .SNA files.
   k) Available from?

3. Speculator (Dave Lawrence)

   a) Emulates 48K Spectrum.
   b) Loads in its own file format.
   c) Saves in its own file format.
   d) No real tape support.
   e) Requirements?
   f) Is extremely fast on an ARM3 machine. To get normal Spectrum speed an
      ARM2 machine or an ARM3 machine with the cache turned off is required.
   g) Status not known - not officially released yet.
   h) It is possible to return to the desktop from the emulator, and then
      re-enter the emulator at the point you left off.
   i) Bad points?
   j) Is not officially available at the moment - any copies circulating are
      pirate copies. As a result, documentation of the file format is not
      complete, and the conversion programs supplied with it do not work
      correctly.
   k) Not yet available?

4. Z80Em (Mike Borcherds [[e-mail]])

   a) Emulates 48K Spectrum.
   b) Loads .RAW, .SNA and .Z80 snapshots with level-loader support. Loads
      tape files from Z80's .TAP files.
   c) Saves .Z80 snapshots and to .TAP tape files.
   d) Can load/save? from/to? sample tapes (.VOC).
   e) Requirements?
   f) Runs a little slowly on an A3010.
   g) Commercial - can be bought along with a CD full of games, the CD coming
      cheaper this way than if bought separately. However, see question 6 in
      the Frequently Asked Questions list (section 1 of this document).
   h) Good points?
   i) Level-loader support expects different filenames from the standard -
      instead of "GAME1.DAT" it wants just "1", etc.
   j) A new version is being worked on that will support v2 and v3 Z80
      snapshots, 128K emulation and possibly .SLT snapshots.
   k) Available from Warm Silence Software; their homepage is at
      http://www.comlab.ox.ac.uk/oucl/users/robin.watts/wss/index.html


Emulators for UNIX/Linux/etc.:
------------------------------

1. Spectrum / French emulator (Jean-Francois Lozevis [[e-mail]])

   a) Emulates 48K Spectrum.
   b) Loads .SNA and .Z80 snapshots.
   c) Saves .SNA snapshots.
   d) No real tape support.
   e) Requires X-Windows (X11) and Linux with an 80386 processor (or above)
      because the emulation code is written in assembler.
   f) Apparently runs at full speed on a 486DX2/66.
   g) Public domain. Author allows modification, just wants to retain his
      credit as the original author, and wouldn't say no to a postcard.
   h) Sound support for Linux via /dev/audio.
   i) Imperfect emulation; Rhino in Sabre Wulf problems (see the Technical
      Information section) and some large BASIC programs don't work. Author
      doesn't know why. Poor user interface.
   j) All messages in French.
   k) Available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/other/french_spectrum.zip

2. xzx v1.0 (Des Herriott [[e-mail] but no reponse from this address])

   a) Emulates 48K/128K/+3 Spectrums, Kempston joystick (with keys).
   b) Loads .SNA and .Z80 snapshots with level-loader support, tape files from
      UNIX files.
   c) Saves .SNA and .Z80 snapshots, tape files to UNIX files.
   d) No real tape support.
   e) Requires X-Windows (X11). Makes heavy use of the MIT-SHM X11 extension,
      and works a good deal slower without it.
   f) Needs approx 486/33 to run at the correct speed (this is from general
      impressions, not exact timings). Sparc 10 or DEC Alpha will run it very
      fast.
   g) Freeware.
   h) Sound support for Sparc and NEC EWS workstations via /dev/audio.
      Sound support for Linux via direct speaker manipulation. X server bell
      audio for most X servers (traps ROM BEEP routine only).
   i) Poor user interface; e.g. no file selector - you have to move to your
      terminal window and type in name of snapshots to load/save.
   j) Author seems to have disappeared! Email address above probably no good.
   k) Available from
      http://hpux.csc.liv.ac.uk/hpux/X11/Misc/xzx-0.5.1.html

3. xzx v2.0 - modified version (Erik Kunze [[e-mail]] &
                                Des Herriott)
   a) Emulates 48/128/+3 with Multiface 128, Interface 1, Kempston Joystick.
   b) Loads .SNA and .Z80 (up to v3.03 format) snapshots with level-loader
      support, tape files from UNIX files.
   c) Saves .SNA and .Z80 snapshots, tape files from UNIX files.
   d) No real tape support.
   e) Requires X11, Linux (for AY emulation).
   f) A bit faster then original xzx 1.0.2.
   g) Still freeware.
   h) Sound support for Sparc via /dev/audio. Sound support for Linux via
      direct speaker manipulation. AY emulation via /dev/dsp (Linux only).
      X server's bell audio for most X servers (traps the ROM BEEP routine
      only).
   i) Still without a file selector. Some known bugs, that Erik has not yet
      found.
   j) Erik still needs beta testers! Mail to [e-mail]. This
      could be the very first Spectrum +3 emulator...
   k) Soon to be available from:
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/other/xzx-2.0.0beta.tar.gz

4. xz80 v0.1e (Ian Collier [[e-mail]])

   a) Emulates 48K Spectrum and ZX Printer (via .XBM image files!).
   b) Loads .SNA and .Z80 snapshots with level-loader support, tape files
      from disk or from Z80's .TAP files.
   c) Saves .SNA snapshots and tape files to disk or to Z80's .TAP files.
   d) Real tape support not known - mentions sound input (e.g. via /dev/audio
      device) but I am unsure what Ian means by this.
   e) Requires X-Windows (X11) or SVGALib (for Linux console version). MIT-SHM
      extension also probably a good idea.
   f) Faster than xzx and x128. The Linux console version runs at about 35%
      real Spectrum speed on a 486SX/25. True-speed emulation without hogging
      the CPU on fast machines.
   g) Freeware (GNU Public License).
   h) Realistic sound output via /dev/audio. Emulates 'stripey border' effect
      - very important ;-)
   i) Poor user interface; e.g. no file selector - you have to move to your
      terminal window and type in name of snapshots to load/save.
   j) No other comments.
   k) Available from author's homepage at
      http://www.comlab.ox.ac.uk/oucl/users/ian.collier/Spectrum/index.html

5. x128 v0.4 (James McKay [[e-mail]] until June 1996)

   a) Emulates 48K/128K Spectrum.
   b) Loads .SNA, .Z80 and .SLT snapshots, and from Z80's .TAP tape files.
   c) Saves .Z80 and .SLT snapshots.
   d) No real tape support.
   e) Requires X-Windows (X11). MIT-SHM extension also a very good idea.
   f) Rather slow; about 25-35% of real Spectrum speed on a 486SX/25 Linux
      box.
   g) Freeware.
   h) Hi-res emulation of screen and left & right border allowing colours
      in an 8x1 block (rainbowing). Now has a file selector and much better
      user interface than previous versions.
   i) Some changeable options require re-compilation.
   j) Also available for DOS.
   k) Available from author's home page (until some time in June 1996) at
      http://diana40.paisley.ac.uk:80/~com40014/ as well as
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/other/x128_0.4.tar.gz

Emulators for Apple Macintosh:
------------------------------

1. MacSpeccy v1.1 (Danny Keogan [[e-mail]])

   a) Emulates 48K Spectrum.
   b) Loads .SNA and (probably) .Z80 snapshots.
   c) Saves?
   d) No real tape support?
   e) Requires 68040.
   f) Seems to be extremely slow.
   g) Freeware?
   h) Allows copying of Spectrum screen to clipboard.
   i) No flash attribute emulation.
   j) The oldest emulator for the Mac.
   k) Available from
      http://hyperarchive.lcs.mit.edu/HyperArchive/Archive/app/
      mac-speccy-11.hqx

2. Mac Spectacle v1.8.2 (Guenter Woigk [[e-mail]])

   a) Emulates 48K/128K Spectrum, joystick (type?).
   b) Loads .SNA and .Z80 snapshots and .SCR screens, tape files from
      Z80's .TAP files.
   c) Saves .SNA and .Z80 snapshots, saves .SCR and .PICT screens.
   d) No real tape support; but there is a program called ZX-Loader to
      enable the use of PowerSpectrum's facilities for this.
   e) Needs MacOS 7.0 or higher, Color QuickDraw and at least a 68020
      CPU or a PowerMAC.
   f) Speed?
   g) Freeware?
   h) Single/double/quadruple sized window, all monitor depths (2 and
      4 bit slow). High-res screen & border effects. Background or
      exclusive execution. Better emulation than other emulators for
      the Mac - so more games run on this one than the others.
   i) Bad points?
   j) The newest and most regularly updated emulator for the Mac.
   k) Available from author's FTP area; get this file first:
      ftp://lst.informatik.uni-erlangen.de//incoming/kio/readme
      or
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/mac/Spectacle-1.8.2.hqx
      and ZX-Loader is available from
      ftp://ftp.nvg.unit.no/pub/sinclair/utils/mac/ZX_Loader_1.0.4.hqx

3. PowerSpectrum v1.0 (Bo Lindbergh [[e-mail]])

   a) Emulates 48K Spectrum, Kempston joystick.
   b) Loads .SNA snapshots.
   c) Saves .SNA snapshots.
   d) Does realtime tape I/O through the microphone jack (this probably
      requires 44 kHz sound hardware).
   e) Requires a PowerMac - won't run on a 680x0 machine.
   f) Runs at true Spectrum speed.
   g) Freeware?
   h) 1x1, 2x2, 3x3, and 4x4 screen emulation. Has perfect sound. Supports all
      undocumented Z80 instructions.
   i) Bad points?
   j) No other comments.
   k) Available from
      http://hyperarchive.lcs.mit.edu/HyperArchive/Archive/app/
      power-spectrum-10-ppc.hqx

Emulators for NeXTStep:
-----------------------

1. NXSpectrum (Ian Stephensen [[e-mail]] &
               Ian Collier [[e-mail]])
   a) Emulates 48K Spectrum. ZX Printer still?
   b) As xz80.
   c) As xz80.
   d) As xz80.
   e) Requirements?
   f) Speed?
   g) Freeware (GNU Public License).
   h) Good points as xz80?
   i) Bad points as xz80?
   j) This is a quick hack of xz80 to make it run under NeXTStep. And yes,
      this is from the same guy who does SoftPC for Insignia!
   k) Available from
      ftp://pitcher.peak.org/pub/next/submissions/
      NXSpectrum.app.NIHS.compressed
      (directory may have changed by the time you read this)

Emulators for Commodore 64: (information from comp.sys.emulators.misc FAQ)
---------------------------

1. Spectrum 48

   a) Emulates Sinclair BASIC only - no Z80 emulation, so no machine code
      programs work. Microdrive emulated via 1541/1571 disk drive.
   b) Loads Microdrive files from disk.
   c) Saves Microdrive files to disk.
   d) No real tape support?
   e) Requires just a basic C64.
   f) Slow - well, it *is* just BASIC and it *is* on a C64!
   g) Freeware?
   h) Allows C64 users to see some of the superiority of Sinclair's master-
      piece (well you try and think of a good point!). And Sinclair BASIC
      is somewhat more useful than Commodore's attempt.
   i) Useless for all but the most BASIC of games (pun intended).
   j) No other comments.
   k) Available from?


******************************************************************************
********************************* WHERE IS...? ********************************
******************************************************************************

1. Imagine/Denton Designs [Stonkers, Frankie goes to Hollywood, etc.]
   o Dougie Burns (programmer)
     Last seen in Glasgow as a used car salesman.
   o Marc Dawson (programmer)
     Project manager for Barbie the Video Game for software house in
     Manchester.
   o John Gibson (programmer - ZZoom/Stonkers)
     Currently working in the Chester office of Psygnosis and has been for
     some time.
   o Fred Gray (musician)
     Became programmer in Liverpool. Works for Psygnosis, as do most of
     Denton Designs. Status uncertain since Sony's take over of Psygnosis.
   o Dave Lawson (director)
     Last seen running Kinetica Software in Birkenhead.
   o Ally Noble (artist) and John Heap (programmer)
     Still own and run Denton Designs.
   * INFO BY:
     Stuart Fotheringham [[e-mail]]
     Andrew Toone [[e-mail]]
     Ralph Ferneyhough [[e-mail]]

2. Gargoyle Games/Faster Than Light [Heavy On The Magick, Lightforce etc.]
   o Roy Carter
     Roy Carter is a registered user of Z80 and has given spoken permission
     to distribute the Gargoyle games. They are (were?) doing things for
     Psygnosis - not all of them game writing.
   * INFO BY:
     Brian Gaff [[e-mail]]
     Andrew Toone [[e-mail]]

3. Design Design [Halls Of The Things, Dark Star etc.]
   o Simon Brattel
     Runs his own company producing system software
   o Graham Stafford
     Works for Psygnosis, as do most of Denton Designs.
   * INFO BY:
     Andrew Toone [[e-mail]]
     Jon Ritman [[e-mail]]

4. LERM [various tape copiers]
   o Robert Evans
     "Not only do I remember Lerm, I did some work for them. Lerm itself was a
      husband and wife company, in the back room, in the traditional fashion.
      The husband was a high-flying software type a.k.a my Maths teacher at
      school."
     "There was a tendency amongst my group of schoolfriends at the time to
      use LERM programs more than anything else, because some of us helped Mr
      Evans (our maths teacher at the time) to write them. If anyone's
      interested, the company name came from a mixture of Robert Evans' and
      his wife's initials."
   * INFO BY:
     David Smith [[e-mail]]
     Scott Wilding [[e-mail]]

5. Ultimate Play The Game/Ashby Computers & Graphics (ACG) [Jetpac,
                                                            Knighlore etc.]
   o Calling themselves Rare and producing console games for Nintendo, e.g.
     Donkey Kong Country and Killer Instinct for the new Nintendo Ultra 64.
   * INFO BY:
     Dylan Cuthbert [[e-mail]]

6. Realtime Graphics [3D StarStrike, Starglider, Carrier Command etc.]
   o Jez San
     Developing 3D systems for anyone with with enough hardware (Nintendo et.
     al.)
   * INFO BY:
     Andrew Toone [[e-mail]]

7. Vortex [Android, TLL, Highway Encounter etc.]
   o Mark Haigh-Hutchinson
     Working for LucasArts, currently on Shadows of the Empire for the
     Nintendo 64. Mark organises the Vortex Emulation Package for several
     machines, including the Spectrum. This contains a number of the Vortex
     games and is freely distributed.
   o Costa Panayi
     Doing some consultancy design work for a children's toys company in the
     south of England (believed to be Chicco).
   * INFO BY:
     Arnt Gulbrandsen [[e-mail]]
     Miguel Melo [[e-mail]]
     Mark Haigh-Hutchinson [[e-mail]]

8. OTHERS:
   o Marcus Berkmann [YS or SU writer - aka Dr. Berkmann]
     Now writing for the Mail on Sunday.
   * INFO BY:
     Keith Willoughby [[e-mail]]

   o John F. Cain [Booty]
     Still lives on the Isle of Man, as he did when he wrote Booty. He has a
     gold cassette of Booty on his wall!
   * INFO BY:
     Mark Walker [[e-mail]]

   o Alan Cox [Blizzard Pass]
     Now doing network stuff; has thought about a Linux version of Blizzard
     Pass. He has a home page where you can retrieve some adventure stuff (but
     not Blizzard Pass itself, as that is owned by whoever bought the rights
     from Tynesoft) - http://shadow.cabi.net/
   * INFO BY:
     Alan Cox [[e-mail]]

   o Mel Croucher [ID]
     Writing for magazines; including the Great Moments In Computing strip for
     Computer Shopper.
   * INFO BY:
     Damien Burke [[e-mail] until June 14th 1996]

   o Robert Erskine [anyone know anything he wrote?] - [e-mail]
     Working for Smallworld Cambridge on GIS.
   * INFO BY:
     Stephen Smith [[e-mail]]

   o Eugene Evans
     Currently working in Chicago at Viacom New Media. He's been there for a
     good few years before which it was Icom Simulations, Inc. the people who
     did the CD-ROM Sherlock Holmes games, T-MON for the Mac, and Dracula
     Unleashed.
   * INFO BY:
     [e-mail] [Brian Leake]

   o Glenn Flood [tape inlay art for Astroblaster and others]
     Programming and drawing still; has a nice web site showing off a lot of
     his artwork at http://www.ftech.net/~floodnet/
   * INFO BY:
     Glenn Flood [[e-mail]]

   o Julian Gollop and Nick Gollop [Chaos, LaserSquad, Rebelstar]
     Owners and programmers of Mythos (UFO, X-COM).
   * INFO BY:
     Miguel Melo [[e-mail]]

   o Simon Goodwin [Crash Tech Tips writer]
     Was still writing for Sinclair QL World when the final issue (July 94)
     came out. Simon Goodwin writes for Amiga magazines and Computer Shopper.
     He was also seen at the Last Sinclair and SAM show in Gloucester. Messing
     with both Speccy emulator for Amiga and hardware Speccy emulation for
     IBM PC.
   * INFO BY:
     Jenni the Satsuma [[e-mail]]
     Brian Gaff [[e-mail]]

   o John Hollis, Nick Lambert
     John Hollis founded Hollis Research, who develop MIDI sequencers
     (including "Trackman" for AtariST).
   * INFO BY:
     Stephen K. Mulrine [[e-mail]]

   o Graeme Kidd [Crash writer]
     News editor for Computer Shopper magazine. At least I think it's the same
     guy...
   * INFO BY:
     Damien Burke [[e-mail] until June 14th 1996]

   o Tony Mack [Gyroscope, Paper Boy, Super Sprint, Championship Sprint]
     Now writes games for the Sega Saturn (currently converting Cybersled to
     it).
   * INFO BY:
     Mark Gordon [[e-mail]]

   o Teresa Maughan [Your Sinclair editor - aka T'zer]
     Now writing for The Mac magazine, either that or someone with the
     same name is...
   * INFO BY:
     Oops, I've lost the posting. Gimme a shout if you were the one who did
     that Alta Vista search!

   o Fergus McNeill [Delta 4 - Bored Of The Rings, The Boggit, etc.]
     Head of design at Sales Curve Interactive (SCi), ex-Storm. SCi have just
     released a Point and Click called "Kingdom 'O Magic" which was designed
     by Fergus. Fergus has kindly agreed to free distribution of the Delta 4
     games, as long as it is *free* - no money may change hands. He cannot
     speak for any of his games with the Abstract Concepts logo, as they are
     owned by Activision.
   * INFO BY:
     Chris Wild [[e-mail]]

   o Neil Pawson [Mighty Magus] - [e-mail]
     Working for Smallworld Cambridge on GIS.
   * INFO BY:
     Stephen Smith [[e-mail]]

   o Dominic Prior [part of Gyron team] - [e-mail]
     Working for Smallworld Cambridge on GIS.
   * INFO BY:
     Stephen Smith [[e-mail]]

   o Jon Ritman [co-author of Batman, Head over Heels, Matchday, etc.]
     Jon Ritman is reading/posting to comp.sys.sinclair and is the director of
     a new(ish) videogame company in the UK called Cranberry Source. Contrary
     to previous assertions in this FAQ, he definitely *didn't* do a Computer
     Science degree at UCL and he and Bernie Drummond wrote only one Gameboy
     game (Monster Max). Jon doesn't care if you copy his old games, but then
     as he says - he doesn't own the rights to them.
   * INFO BY:
     Vartan Narinian [[e-mail]]
     Peter Watsons [[e-mail]]
     Jon Ritman [[e-mail]]

   o Mike Singleton [Lords Of Midnight, Doomdark's Revenge etc.]
     Mike Singleton is alive and well and writing Lords Of Midnight games.
     for the IBM PC. Chris Wild did PC versions of Lords of Midnight and
     Doomdark's Revenge.
   * INFO BY:
     Chris Wild [[e-mail]]

   o Matthew Smith [Styx, Manic Miner, Jet Set Willy]
     Nothing concrete on the father of the miner :(
     Previous rumours range from him working in some computer store in the
     south of England to the latest; a motorbike mechanic called Mat living in
     a commune in the Netherlands; he mentioned to someone that he "wrote some
     video games in the 80's, got burnt out, ended up in a mental
     institution".
   * INFO BY:
     Stephen Smith [[e-mail]]

   o Phil South [aka Snouty; Your Sinclair writer]
     Writes for Computer Shopper magazine.
   * INFO BY:
     Damien Burke [[e-mail] until June 14th 1996]

   o Kevin Thoms [Football Manager]
     Currently working as a Windows consultant/programmer.
   * INFO BY:
     Miguel Melo [[e-mail]]

   o Sandy White (Ant Attack, Zombie Zombie)
     Currently working on a super new top secret engine while laying about on
     a beach in Greece.
   * INFO BY:
     Jon Ritman [[e-mail]

9. Spectrum people reading comp.sys.sinclair
   o Simon Cooke [[e-mail]] was Your Sinclair's technical
     editor, and has put up extracts from YS issues at his web site at
     http://jumper.mcc.ac.uk/~simonc/ys.
   o Alan Fothergill [[e-mail]] from Imagine.
   o Stuart Fotheringham [[e-mail]] did work on those
     beautiful graphics in Odin games Nodes of Yesod, Robin O' the Wood, Arc
     of Yesod, and Heartland.
   o Paul Holmes [[e-mail]] from Elite wrote and co-wrote Robotron
     2084, Bomb Jack I & II, Wild West Hero, Dustman, designed and co-designed
     Grand National, Frank Bruno's Boxing and others.
   o Mark Haigh-Hutchinson [[e-mail]] of Vortex pops up occasionally,
     mostly to mention updates to the Vortex Emulation Package, which is a
     collection of Vortex games (TLL, Highway Encounter etc.) and instructions
     for them, and is freely distributable.
   o John Ritman [[e-mail]] of Head Over Heels fame. Also
     co-wrote Batman, Matchday and other excellent games with Bernie Drummond.
   o Duncan Sinclair [[e-mail]] worked on an unfinished
     Tapper with Paul Holmes.


******************************************************************************
******************************** FILE FORMATS ********************************
******************************************************************************

This section will be expanded as I get the time to do so; if you are desperate
for information about a particular format right now, a good source of
information is the source to SPConv v1.10; available from (among other
locations): ftp://ftp.nvg.unit.no/pub/sinclair/utils/generic/spcnv110.zip

============================== Snapshot formats ==============================

Those handled by SPConv v1.10 are marked with an asterisk (*):

.ACH or .archimedes *
        Snapshots used by !Speccy. .ACH is the extension SPConv uses for these
        files; so that filename-challenged operating systems like DOS can
        handle such files for conversion purposes.
.PRG *  Program file used by Specem.
.RAW *  Raw memory dump from a real Spectrum; just the 48Kb of RAM and a CODE
        header on the front.
.SEM    Snapshots used by ZX Spectrum-Emulator, the German PC-based emulator.
.SIT *  Situation file used by Sinclair v2.00.
.SLT    Super level loader snapshot. Used by x128 and WSpecEm at time of
        writing. Basically a v2/3 Z80 snapshot with level data appended.
.SNA or .snap or .snapshot *
        Mirage Microdrive snapshot format, used by most emulators.
.SNA    128Kb version of SNA. Distinguished by file size of 131103 bytes
        instead of 49179 bytes for 48Kb version.
.SNX *  Extended version of SNA, used by Speccy on the Atari ST.
.SP  *  Snapshots used by SPECTRUM.
.SP  *  Snapshots used by VGASPEC.
.SP     Snapshots used by ZX Spectrum (Mac emulator).
.Z80 *  Snapshots used by Z80 and several other emulators. Three versions in
        existence, the latest of which (v3) is not supported by all these
        emulators. Very flexible; support for SamRam, 128K snapshots, etc.
.ZX  *  Snapshots used by KGB.

For the purposes of these descriptions, the following definitions apply:

byte = byte-sized variable; word = 2 bytes, long = 4 bytes. All stored in
little-endian (Intel) format unless otherwise stated.

a) .SLT (super level loader trap used by x128 v0.4+, WSpecEm etc.)

   The level loader trap has one annoying disadvantage; lots of extra files
   lying around for each game. The super level loader was thought up (by me,
   natch :-)) to replace this multi-file format with a single snapshot file
   containing all the level data files. It has been designed in co-operation
   with James McKay (x128), Gerton Lunter (Z80), Rui Ribeiro (WSpecEm) and
   Darren Salt (helping with Z80Em), so is well-supported already. The
   format was designed with future expansion in mind, as you will see.

            Size   Description
   ------------------------------------------------------------------------
            varies bytes  Z80 snapshot (version 2+)
            3      bytes  Three null bytes (compatibility; see below)
            3      bytes  "SLT" (signature)
   ---- the following blocks make up a table to access the data files -----
            2      word   data type (0 = end of table, 1 = level data)
            2      word   data identifier (for type 1 this is level number)
            4      long   data length
            2      word   data type (0 = end of table, 1 = level data)
            2      word   data identifier (for type 1 this is level number)
            4      long   data length
            ... and so on
   ---- the following blocks are the data files themselves ----------------
            varies bytes data
            varies bytes data
            ... and so on
   ------------------------------------------------------------------------

   The three null bytes after the end of the snapshot are for compatibility
   reasons; older versions of Z80 would crash if the extra data was just
   appended to the snapshot. With these three null bytes, they just complain
   about an error in the snapshot file instead. This, of course, presumes you
   have renamed the .SLT file to .Z80 and attempted to load it into an older
   emulator!

   After the "SLT" signature, there is a table of data types and sizes. Only
   data types 0 (end of table) and 1 (level data) are supported at the moment,
   so if other values are encountered an emulator should ignore that data
   block.

   To read a level data file using .SLT, the emulator should find the correct
   entry in the table (type = 1, identifier matching the A register when the
   ED/FB instruction was encountered), get its size from the table and
   calculate its position from the total of sizes of data blocks previous to
   the required one, added to the position of the end of the table. E.g., to
   load level 2 from a .SLT snapshot with this table:

   Position  Size  Value  Description
   ------------------------------------------------------------------------
   40000     2     1      data type = level data
   40002     2     1      data identifier = level 1
   40004     4     256    data length = 256 bytes
   40008     2     1      data type = level data
   40010     2     2      data identifier = level 2
   40012     4     128    data length = 128 bytes
   40016     2     0      data type = end of table
   40018     2     *      data identifier = unused (may as well be zero)
   40020     4     *      data length =  unused (may as well be zero)
   40024     256   *      data block for level 1
   40280     128   *      data block for level 2
   ------------------------------------------------------------------------
   (* = could be anything)

   So, the size of level 2 is 128 bytes, and its located at the end of the
   table (40024) + the length of all previous blocks (just 256 here) = 40280.

   Level data is packed in the same way as Z80 snapshot memory banks are.

   The trainspotter award seekers of you may wonder why a whole word is used
   for the data identifier; after all, this is the level number and is held in
   the A register, so could be just a byte. For level data, correct. But
   future expansion is better served by a word. For the same reasons, the data
   length is held as a long word instead of just a word; level data will never
   exceed 64Kb (indeed, could not even be as much as 48Kb), but future data
   types may do so. One example; embedding a scan of a game's inlay card in
   the file is possible, and that file could exceed 64Kb easily.

   See http://www.cs.bham.ac.uk/~dmb/speccy/edfb.html for my own proposals
   for future data types for inclusion in .SLT snapshots.

b) .SNA, .snap or .snapshot (Mirage Microdrive format used by many emulators)

   This format is the most well-supported of all snapshot formats (though Z80
   is close on its heels) but has a drawback:

      As the program counter is pushed onto the stack so that a RETN
      instruction can restart the program, 2 bytes of memory are overwritten.
      This will usually not matter; the game (or whatever) will have stack
      space that can be used for this. However, if this space is all in use
      when the snap is made, memory below the stack space will be corrupted.
      According to Rui Ribeiro, the effects of this can sometimes be avoided
      by replacing the corrupted bytes with zeros; e.g. take the PC from the,
      stack pointer, replace that word with 0000 and then increment SP. This
      worked with snapshots of Batman, Bounder and others which had been
      saved at critical points. Theoretically, this problem could cause a
      complete crash on a real Spectrum if the stack pointer happened to be
      at address 16384; the push would try and write to the ROM. How different
      emulators handle this is not something I know...

   When the registers have been loaded, a RETN command is required to start
   the program. IFF2 is short for interrupt flip-flop 2, and for all practical
   purposes is the interrupt-enabled flag. Set means enabled.

   Offset   Size   Description
   ------------------------------------------------------------------------
   0        1      byte   I
   1        8      word   HL',DE',BC',AF'
   9        10     word   HL,DE,BC,IY,IX
   19       1      byte   Interrupt (bit 2 contains IFF2, 1=EI/0=DI)
   20       1      byte   R
   21       4      words  AF,SP
   25       1      byte   IntMode (0=IM0/1=IM1/2=IM2)
   26       1      byte   BorderColor (0..7, not used by Spectrum 1.7)
   27       49152  bytes  RAM dump 16384..65535
   ------------------------------------------------------------------------
   Total: 49179 bytes

c) .SNA (128Kb version) (SP_EMU)

   This is simply the SNA format extended to include the extra memory banks
   of the 128K/+2 machines, and fixes the problem with the PC being pushed
   onto the stack - now it is located in an extra variable in the file (and
   is not pushed onto the stack at all) The first 49179 bytes of the
   snapshot are otherwise exactly as described above, so the full
   description is:

   Offset   Size   Description
   ------------------------------------------------------------------------
   0        27     bytes  SNA header (see above)
   27       16Kb   bytes  RAM bank 5 \
   16411    16Kb   bytes  RAM bank 2  } - as standard 48Kb SNA file
   32795    16Kb   bytes  RAM bank n / (currently paged bank)
   49179    2      word   PC
   49181    1      byte   port 7FFD setting
   49182    1      byte   (unknown - padding for above byte?)
   49183    16Kb   bytes  remaining RAM banks in ascending order
   ...
   ------------------------------------------------------------------------
   Total: 131103 or 147487 bytes

   The third RAM bank saved is always the one currently paged, even if this
   is page 5 or 2 - in this case, the bank is actually included twice. The
   remaining RAM banks are saved in ascending order - e.g. if RAM bank 4 is
   paged in, the snapshot is made up of banks 5, 2 and 4 to start with, and
   banks 0, 1, 3, 6 and 7 afterwards. If RAM bank 5 is paged in, the
   snapshot is made up of banks 5, 2 and 5 again, followed by banks 0, 1, 3,
   4, 6 and 7.

d) .SP file format used in "ZX Spectrum", the ZX Spectrum emulator for
   Macintosh from Lorenzo Jose Ayuda Serrano.

   Offset   Size   Description
   ------------------------------------------------------------------------
   0        2      byte   "SP" (signature)
   2        2      word   Program length in bytes (49152 bytes)
   4        2      word   Program location (16384)
   6        8      word   BC,DE,HL,AF
   14       4      word   IX,IY
   18       8      word   BC',DE',HL',AF'
   26       2      byte   R,I
   28       4      word   SP,PC
   32       2      word   0 (reserved for future use)
   34       1      byte   Border color
   35       1      byte   0 (reserved for future use)
   36       2      word   Status word
   ------------------------------------------------------------------------

   Status word:
   Bit     Description
   ------------------------------------------------------------------------
   15-8    Reserved for future use
    7-6    Reserved for internal use (0)
      5    Flash: 0=INK/1=PAPER
      4    Interrupt pending for execution
      3    Reserved for future use
      2    IFF2 (internal use)
      1    Interrupt Mode: 0=IM1/1=IM2
      0    IFF1: 0=DI/1=EI

e) .ZX (KGB v.1.2-1.3) [Contributed by Troels Norgaard]
   All values stored in big-endian format; on 680x0 the most significant
   byte goes first.

   Offset   Size   Description
   ------------------------------------------------------------------------
   0        49284  bytes  RAM dump 16252..65535
   49284    132    bytes  unused, make 0
   49416    10     word   10,10,4,1,1 (different settings)
   49426    1      byte   InterruptStatus (0=DI/1=EI)
   49427    2      byte   0,3
   49429    1      byte   ColorMode (0=BW/1=Color)
   49430    4      long   0
   49434    16     word   BC,BC',DE,DE',HL,HL',IX,IY
   49450    2      byte   I,R
   49452    2      word   0
   49454    8      byte   0,A',0,A,0,F',0,F
   49462    8      word   0,PC,0,SP
   49470    2      word   SoundMode (0=Simple/1=Pitch/2=RomOnly)
   49472    2      word   HaltMode  (0=NoHalt/1=Halt)
   49474    2      word   IntMode   (-1=IM0/0=IM1/1=IM2)
   49476    10     bytes  unused, make 0
   ------------------------------------------------------------------------
   Total: 49486 bytes

f) .Z80 (Z80) [from Z80 documentation]

The old .Z80 snapshot format (for version 1.45 and below) looks like this:

        Offset  Length  Description
        ---------------------------
        0       1       A register
        1       1       F register
        2       2       BC register pair (LSB, i.e.  C, first)
        4       2       HL register pair
        6       2       Program counter
        8       2       Stack pointer
        10      1       Interrupt register
        11      1       Refresh register (Bit 7 is not significant!)
        12      1       Bit 0  : Bit 7 of the R-register
                        Bit 1-3: Border colour
                        Bit 4  : 1=Basic SamRom switched in
                        Bit 5  : 1=Block of data is compressed
                        Bit 6-7: No meaning
        13      2       DE register pair
        15      2       BC' register pair
        17      2       DE' register pair
        19      2       HL' register pair
        21      1       A' register
        22      1       F' register
        23      2       IY register (Again LSB first)
        25      2       IX register
        27      1       Interrupt flipflop, 0=DI, otherwise EI
        28      1       IFF2 (not particularly important...)
        29      1       Bit 0-1: Interrupt mode (0, 1 or 2)
                        Bit 2  : 1=Issue 2 emulation
                        Bit 3  : 1=Double interrupt frequency
                        Bit 4-5: 1=High video synchronisation
                                 3=Low video synchronisation
                                 0,2=Normal
                        Bit 6-7: 0=Cursor/Protek/AGF joystick
                                 1=Kempston joystick
                                 2=Sinclair 2 Left joystick (or user
                                   defined, for version 3 .Z80 files)
                                 3=Sinclair 2 Right joystick

    Because of compatibility, if byte 12 is 255, it has to be regarded as
    being 1.  After this header block of 30 bytes the 48K bytes of Spectrum
    memory follows in a compressed format (if bit 5 of byte 12 is one).
    The compression method is very simple: it replaces repetitions of at
    least five equal bytes by a four-byte code ED ED xx yy, which stands
    for "byte yy repeated xx times".  Only sequences of length at least 5
    are coded. The exception is sequences consisting of ED's; if they are
    encountered, even two ED's are encoded into ED ED 02 ED.  Finally,
    every byte directly following a single ED is not taken into a block,
    for example ED 6*00 is not encoded into ED ED ED 06 00 but into ED 00
    ED ED 05 00. The block is terminated by an end marker, 00 ED ED 00.

    That's the format of .Z80 files as used by versions up to 1.45.
    Starting from version 2.0, a different format is used, since from then
    on also 128K snapshots had to be supported.  This new format is used
    for all snapshots, either 48K or 128K.

    Version 2.01 and 3.0 .Z80 files start with the same 30 byte header as
    old .Z80 files used.  Bit 4 and 5 of the flag byte have no meaning
    anymore, and the program counter (byte 6 and 7) are zero to signal a
    version 2.01 or version 3.0 snapshot file.

    After the first 30 bytes, the additional header follows:

        Offset  Length  Description
        ---------------------------
      * 30      2       Length of additional header block (see below)
      * 32      2       Program counter
      * 34      1       Hardware mode (see below)
      * 35      1       If in SamRam mode, bitwise state of 74ls259.
                        For example, bit 6=1 after an OUT 31,13 (=2*6+1)
                        If in 128 mode, contains last OUT to 7ffd
      * 36      1       Contains 0FF if Interface I rom paged
      * 37      1       Bit 0: 1 if R register emulation on
                        Bit 1: 1 if LDIR emulation on
      * 38      1       Last OUT to fffd (soundchip register number)
      * 39      16      Contents of the sound chip registers
        55      2       Low T state counter
        57      1       Hi T state counter
        58      1       Flag byte used by Spectator (QL spec. emulator)
                        Ignored by Z80 when loading, zero when saving
        59      1       0FF if MGT Rom paged
        60      1       0FF if Multiface Rom paged. Should always be 0.
        61      1       0FF if 0-8191 is RAM
        62      1       0FF if 8192-16383 is RAM
        63      10      5x keyboard mappings for user defined joystick
        73      10      5x ascii word: keys corresponding to mappings above
        83      1       MGT type: 0=Disciple+Epson,1=Discipls+HP,16=Plus D
        84      1       Disciple inhibit button status: 0=out, 0ff=in
        85      1       Disciple inhibit flag: 0=rom pageable, 0ff=not

    The value of the word at position 30 is 23 for version 2.01 files, and
    54 for version 3.0 files.  The starred fields are the ones that
    constitute the version 2.01 header, and their interpretation has
    remained unchanged except for byte 34:

        Value:          Meaning in v2.01        Meaning in v3.0
        -------------------------------------------------------
        0               48k                     48k
        1               48k + If.1              48k + If.1
        2               SamRam                  48k + M.G.T.
        3               128k                    SamRam
        4               128k + If.1             128k
        5               -                       128k + If.1
        6               -                       128k + M.G.T.

    The hi T state counter counts up modulo 4.  Just after the ULA
    generates its once-in-every-20-ms interrupt, it is 3, and is increased
    by one every 5 emulated milliseconds.  In these 1/200s intervals, the
    low T state counter counts down from 17472 to 0, which make a total of
    69888 T states per frame.

    The 5 ascii words (high byte always 0) at 73-82 are the keys
    corresponding to the joystick directions left, right, down (!), up (!),
    fire respectively.  Shift, Symbol Shift, Enter and Space are denoted by
    [,],/,\ respectively.  The ascii values are used only to display the
    joystick keys; the information in the 5 keyboard mapping words
    determine which key is actually pressed (and should correspond to the
    ascii values).  The low byte is in the range 0-7 and determines the
    keyboard row.  The high byte is a mask byte and determines the column.
    Enter for example is stored as 0x0106 (row 6 and column 1) and 'g' as
    0x1001 (row 1 and column 4).

    Byte 60 must be zero, because the contents of the Multiface RAM is not
    saved in the snapshot file.  If the Multiface was paged when the
    snapshot was saved, the emulated program will most probably crash when
    loaded back.

    Bytes 61 and 62 are a function of the other flags, such as byte 34, 59,
    60 and 83.

    Hereafter a number of memory blocks follow, each containing the
    compressed data of a 16K block.  The compression is according to the
    old scheme, except for the end-marker, which is now absent.  The
    structure of a memory block is:

        Byte    Length  Description
        ---------------------------
        0       2       Length of data (without this 3-byte header)
        2       1       Page number of block
        3       [0]     Compressed data

    The pages are numbered, depending on the hardware mode, in the
    following way:

        Page    In '48 mode     In '128 mode    In SamRam mode
        ------------------------------------------------------
         0      48K rom         rom (basic)     48K rom
         1      Interface I, Disciple or Plus D rom, according to setting
         2      -               rom (reset)     samram rom (basic)
         3      -               page 0          samram rom (monitor,..)
         4      8000-bfff       page 1          Normal 8000-bfff
         5      c000-ffff       page 2          Normal c000-ffff
         6      -               page 3          Shadow 8000-bfff
         7      -               page 4          Shadow c000-ffff
         8      4000-7fff       page 5          4000-7fff
         9      -               page 6          -
        10      -               page 7          -
        11      Multiface rom   Multiface rom   -

    In 48K mode, pages 4,5 and 8 are saved.  In SamRam mode, pages 4 to 8
    are saved.  In '128 mode, all pages from 3 to 10 are saved.  This
    version saves the pages in numerical order.  There is no end marker.

================================ Tape formats: ===============================

.BLK    Tape format used by Sinclair v2.00; seems to be identical to Z80's
        .TAP files.
.SPC    Tape format used by SP, the Polish emulator.
.TAP    Tape format used by Z80; supports headerless files and not much else.
.TAP    Tape format used by Warajevo - supports lots of features; turbo-load,
        headerless files, etc.
.VOC    Straight sound sample of a tape; used by several emulators.
.ZXS    Very flexible tape format, not actually used by any emulators - used
        to store real Spectrum tapes in a digital format. All come from the
        ZX Spectrum Software Museum (http://relcom.eu.net/zx/).

a) .TAP and .BLK (Z80, Sinclair, several others) [from Z80 documentation]

The .TAP files contain blocks of tape-saved data.  All blocks start with two
bytes specifying how many bytes will follow (not counting the two length
bytes). Then raw tape data follows, including the flag and checksum bytes.
The checksum is the bitwise XOR of all bytes including the flag byte. For
example, when you execute the line SAVE "ROM" CODE 0,2 this will result:

             |------ Spectrum-generated data -------|       |---------|

       13 00 00 03 52 4f 4d 7x20 02 00 00 00 00 80 f1 04 00 ff f3 af a3

       ^^^^^...... first block is 19 bytes (17 bytes+flag+checksum)
             ^^... flag byte (A reg, 00 for headers, ff for data blocks)
                ^^ first byte of header, indicating a code block

       file name ..^^^^^^^^^^^^^
       header info ..............^^^^^^^^^^^^^^^^^
       checksum of header .........................^^
       length of second block ........................^^^^^
       flag byte ............................................^^
       first two bytes of rom .................................^^^^^
       checksum (checkbittoggle would be a better name!).............^^

Note that it is possible to join .TAP files by simply stringing them together,
for example COPY /B FILE1.TAP + FILE2.TAP ALL.TAP

For completeness, I'll include the structure of a tape header. A header always
consists of 17 bytes:

        Byte    Length  Description
        ---------------------------
        0       1       Type (0,1,2 or 3)
        1       10      Filename (padded with blanks)
        11      2       Length of data block
        13      2       Parameter 1
        15      2       Parameter 2

The type is 0,1,2 or 3 for a Program, Number array, Character array or Code
file. A SCREEN$ file is regarded as a Code file with start address 16384 and
length 6912 decimal. If the file is a Program file, parameter 1 holds the
autostart line number (or a number >=32768 if no LINE parameter was given) and
parameter 2 holds the start of the variable area relative to the start of the
program. If it's a Code file, parameter 1 holds the start of the code block
when saved, and parameter 2 holds 32768. For data files finally, the byte at
position 14 decimal holds the variable name.

=============================== Other formats: ===============================

.DAT    Data files used by level-loader versions of a game (Z80Em does not use
        a .DAT extension at all; instead files are just numbered, e.g. "1"
        instead of "GAME1.DAT").
.MDR    Microdrive cartridge file as used by Spectator, Carlo Delhez' Speccy
        emulator for the QL, and other emulators - xzx and Z80.
.OUT    OUT logs from Z80.
.SCR    Screendumps from Z80 (actually, may be any extension). This is just
        the 6912 bytes of the Spectrum's screen; 6144 bytes of pixel data (in
        that horrendous layout we all know and love) followed by 768 bytes of
        attribute data.

a) .MDR (Spectator, xzx, Z80) [from Z80 documentation]

The following information is adapted from Carlo's documentation. It can also
be found in the 'Spectrum Microdrive Book', by Ian Logan (co-writer of the
excellent 'Complete Spectrum ROM Disassembly').

A cartridge file contains 254 'sectors' of 543 bytes each, and a final byte
flag which is non-zero is the cartridge is write protected, so the total
length is 137923 bytes. On the cartridge tape, after a GAP of some time the
Interface I writes 10 zeros and 2 FF bytes (the preamble), and then a
fifteen byte header-block-with-checksum. After another GAP, it writes a
preamble again, with a 15-byte record-descriptor-with-checksum (which has a
structure very much like the header block), immediately followed by the data
block of 512 bytes, and a final checksum of those 512 bytes. The preamble is
used by the Interface I hardware to synchronise, and is not explicitly used by
the software. The preamble is not saved to the microdrive file:

    Offset Length Name    Contents
    ------------------------------
      0      1   HDFLAG   Value 1, to indicate header block
      1      1   HDNUMB   sector number (values 254 down to 1)
      2      2            not used
      4     10   HDNAME   microdrive cartridge name (blank padded)
     14      1   HDCHK    header checksum (of first 14 bytes)

     15      1   RECFLG   - bit 0: always 0 to indicate record block
                          - bit 1: set for the EOF block
                          - bit 2: reset for a PRINT file
                          - bits 3-7: not used (value 0)
     16      1   RECNUM   data block sequence number (value starts at 0)
     17      2   RECLEN   data block length (<=512, LSB first)
     19     10   RECNAM   filename (blank padded)
     29      1   DESCHK   record descriptor checksum (of previous 14 bytes)
     30    512            data block
    542      1   DCHK     data block checksum (of all 512 bytes of data
                           block, even when not all bytes are used)
    ---------
    254 times

(Actually, this information is 'transparent' to the emulator. All it does is
store 2 times 254 blocks in the .MDR file as it is OUTed, alternatingly of
length 15 and 528 bytes. The emulator does check checksums, see below; the
other fields are dealt with by the emulated Interface I software.)

A used record block is either an EOF block (bit 1 of RECFLG is 1) or contains
512 bytes of data (RECLEN=512, i.e.  bit 1 of MSB is 1). An empty record block
has a zero in bit 1 of RECFLG and also RECLEN=0. An unusable block (as
determined by the FORMAT command) is an EOF block with RECLEN=0.

The three checksums are calculated by adding all the bytes together modulo
255; this will never produce a checksum of 255. Possibly, this is the value
that is read by the Interface I if there's no or bad data on the tape.

In normal operation, all first-fifteen-byte blocks of each header or record
block will have the right checksum. If the checksum is not right, the block
will be treated as a GAP. For instance, if you type OUT 239,0 on a normal
Spectrum with interface I, the microdrive motor starts running and the
cartridge will be erased completely in 7 seconds. CAT 1 will respond with
'microdrive not ready'. Try it on the emulator...

b) .SCR (Z80, WSpecEm)

These files are just Spectrum screen dumps, and are simply the 6912 bytes of
pixel and attribute data found at address 16384, stored on disk in exactly the
same way as they are stored in memory.

******************************************************************************
*************************** TECHNICAL INFORMATION ****************************
******************************************************************************

================================= Z80 CPU ====================================

I had hoped to add some information from several threads on the newsgroup
(Z80 emulation related facts, BIT and the flags and Z80 interrupts) but just
never got the time, and probably won't have the opportunity to do so now for
several months - if the mean time someone wants to compile the relevant
information together so I can just paste it in, I'd be most grateful ;)

This section is based on the text contributed by Gerton Lunter, author of the
"Z80" Spectrum emulator. Marat Fayzullin made some changes which didn't change
the content and Ian Collier and several others have contributed some extra
information (some of which conflicts with Gertons - further contributions
welcome!).

Most Z80 opcodes are one byte long, not counting a possible byte or word
operand. The four opcodes CB, DD, ED and FD are shift opcodes: they change the
meaning of the opcode following them.

a) CB opcodes:
  There are 248 different CB opcodes.
The block CB 30 to CB 37 is missing from the official list. These
instructions, usually denoted by the mnemonic SLL, Shift Left Logical,
shift left the operand and make bit 0 always one. These instructions are
quite commonly used. For example, Bounder and Enduro Racer use them.

b) DD and FD opcodes:
  The DD and FD opcodes precede instructions using the IX and IY
registers. If you look at the instructions carefully, you see how they
work:

    2A nn      LD HL,(nn)
    DD 2A nn   LD IX,(nn)
    7E         LD A,(HL)
    DD 7E d    LD A,(IX+d)

A DD opcode simply changes the meaning of HL in the next instruction. If a
memory byte is addressed indirectly via HL, as in the second example, a
displacement byte is added. Otherwise the instruction simply acts on IX
instead of HL (A notational awkwardness, that will only bother assembler
and disassembler writers: JP (HL) is not indirect; it should have been
denoted by JP HL). If a DD opcode precedes an instruction that doesn't use
the HL register pair at all, the instruction is executed as usual.
However, if the instruction uses the H or L register, it will now use the
high or low halves of the IX register! Example:

    44         LD B,H
    FD 44      LD B,IYh

These types of 'undocumented' instructions are used in very many programs. By
the way, many DD or FD opcodes after each other will effectively be NOPs,
doing nothing except repeatedly setting the flag "treat HL as IX" (or IY) and
taking up 4 T states (But try to let MONS disassemble such a block.).

From Joseph S. Myers [[e-mail]]:
[DD and FD have no effect on ED instructions, or on EX DE,HL. If an
instruction references both (HL), and one of H and L, then (HL) becomes
(IX+d) or (IY+d), but H or L stays as it is. For example, DD6601 is
LD H,(IX+01).

DDCB and FDCB prefix instructions in which the next byte is a displacement
byte, and the byte after that is the instruction byte. If the CB instruction
references (HL), the effect is as expected; otherwise, the instruction seems
to act on (IX+d) or (IY+d), and, if the instruction is such as to change the
value acted on (any instruction other than BIT), the new value is loaded into
the register the CB instruction would act on. Thus:

CB07 is RLC A; DDCB0107 is effectively RLC (IX+01) followed by LD A,(IX+01).]

c) ED opcodes:
   There are a number of unofficial ED instructions, but none of them are very
useful. The ED opcodes in the range 00-3F and 80-FF (except for the block
instructions of course) do nothing at all but taking up 8 T states and
incrementing the R register by 2.  Most of the unlisted opcodes in the range
40-7F do have an effect, however. The complete list:

(*  = not official, i.e. not listed in Zilog documentation)
(++ = documented in Spectrum manual)

        ED40   IN B,(C)                 ED60   IN H,(C)
        ED41   OUT (C),B                ED61   OUT (C),H
        ED42   SBC HL,BC                ED62   SBC HL,HL
        ED43   LD (nn),BC               ED63 * LD (nn),HL    ++
        ED44   NEG                      ED64 * NEG
        ED45   RETN                     ED65 * RET
        ED46   IM 0                     ED66 * IM 0
        ED47   LD I,A                   ED67   RRD
        ED48   IN C,(C)                 ED68   IN L,(C)
        ED49   OUT (C),C                ED69   OUT (C),L
        ED4A   ADC HL,BC                ED6A   ADC HL,HL
        ED4B   LD BC,(nn)               ED6B * LD HL,(nn)    ++
        ED4C * NEG                      ED6C * NEG
        ED4D   RETI                     ED6D * RET
        ED4E * IM 0/1                   ED6E * IM 0/1
        ED4F   LD R,A                   ED6F   RLD
        ED50   IN D,(C)                 ED70 * IN (C)        ++ as IN F,(C)
        ED51   OUT (C),D                ED71 * OUT (C),0
        ED52   SBC HL,DE                ED72   SBC HL,SP
        ED53   LD (nn),DE               ED73   LD (nn),SP
        ED54 * NEG                      ED74 * NEG
        ED55 * RET                      ED75 * RET
        ED56   IM 1                     ED76 * IM 1
        ED57   LD A,I                   ED77 * NOP
        ED58   IN E,(C)                 ED78   IN A,(C)
        ED59   OUT (C),E                ED79   OUT (C),A
        ED5A   ADC HL,DE                ED7A   ADC HL,SP
        ED5B   LD DE,(nn)               ED7B   LD SP,(nn)
        ED5C * NEG                      ED7C * NEG
        ED5D * RET                      ED7D * RET
        ED5E   IM 2                     ED7E * IM 2
        ED5F   LD A,R                   ED7F * NOP

The ED70 instruction reads from port (C), just like the other instructions,
but throws away the result. It does change the flags in the same way as the
other IN instructions, however. The ED70 instruction *is* documented in at
least two other publications beside the original Spectrum manual - one of
which is an SGS Z80 data booklet.

The ED71 instruction OUTs a byte zero to port (C). In fact the instructions
INI and OUTI do almost exactly the same as the proposed action for ED70 and
ED71 as well as incrementing the registers

The IM 0/1 instruction puts the processor in either IM 0 or 1 (undetermined
at this time). The SGS booklet says that there are two flip-flops which
determine the interrupt mode and are set by the IM instructions. The possible
values are:

  00  IM 0
  01  not used
  10  IM 1
  11  IM 2

...so it is entirely possible that the IM 0/1 instruction sets these registers
to 01. What the Z80 does when this happens is anyone's guess.


d) About the R register:
   This is not really an undocumented feature, although I have never seen any
thorough description of it anywhere. The R register is a counter that is
updated every instruction, where DD, FD, ED and CB are to be regarded as
separate instructions. So shifted instruction will increase R by two. There's
an interesting exception: doubly-shifted opcodes, the DDCB and FDCB ones,
increase R by two too. LDI increases R by two, LDIR increases it by 2 times
BC, as does LDDR etcetera.  The sequence LD R,A/LD A,R increases A by two,
except for the highest bit: this bit of the R register is never changed. This
is because in the old days everyone used 16 Kbit chips. Inside the chip the
bits where grouped in a 128x128 matrix, needing a 7 bit refresh cycle.
Therefore ZiLOG decided to count only the lowest 7 bits. You can easily check
that the R register is really crucial to memory refresh. Assemble this program:

        ORG 32768
        DI
        LD B,0
    L1: XOR A
        LD R,A
        DEC HL
        LD A,H
        OR L
        JR NZ,L1
        DJNZ L1
        EI
        RET

It will take about three minutes to run.  Look at the upper 32K of memory,
for instance the UDG graphics.  It will have faded.  Only the first few bytes
of each 256 byte block will still contain zeros, because they were refreshed
during the execution of the loop. The ULA took care of the refreshing of the
lower 16K (This example won't work on the emulator, of course!).

e) Undocumented flags:
   This undocumented "feature" of Z80 has its effect on programs like Sabre
Wulf, Ghosts'n Goblins and Speedlock. Bits 3 and 5 of the F register are not
used. They can contain information, as you can readily figure out by PUSHing
AF onto the stack and then POPping some it into another pair of registers.
Furthermore, sometimes their values change. I found the following empirical
rule:

    The values of bits 7, 5 and 3 follow the values of the corresponding
    bits of the last 8 bit result of an instruction that changed the usual
    flags.

For instance, after an ADD A,B those bits will be identical to the bits of
the A register (Bit 7 of F is the sign flag, and fits the rule exactly). An
exception is the CP x instruction (x=register, (HL) or direct argument). In
this case the bits are copied from the argument.

If the instruction is one that operates on a 16 bit word, the 8 bits of the
rule are the highest 8 bits of the 16 bit result - that was to be expected
since the S flag is extracted from bit 15.

Ghosts'n Goblins use the undocumented flag due to a programming error. The
rhino in Sabre Wulf walks backward or keeps running in little circles in a
corner, if the (in this case undocumented) behaviour of the sign flag in the
BIT instruction isn't right. I quote:

        AD86    DD CB 06 7E        BIT 7,(IX+6)
        AD8A    F2 8F AD           JP P,#AD8F

An amazing piece of code!  Speedlock does so many weird things that all must
be exactly right for it to run. Finally, the '128 ROM uses the AF register to
hold the return address of a subroutine for a while.

f) Interrupt flip-flops IFF1 and IFF2:
   There seems to be a little confusion about these. These flip flops are
simultaneously set or reset by the EI and DI instructions. IFF1 determines
whether interrupts are allowed, but its value cannot be read. The value of
IFF2 is copied to the P/V flag by LD A,I and LD A,R. When an NMI occurs, IFF1
is reset, thereby disallowing further (maskable) interrupts, but IFF2 is left
unchanged. This enables the NMI service routine to check whether the
interrupted program had enabled or disabled maskable interrupts. So, Spectrum
snapshot software can only read IFF2, but most emulators will emulate both,
and then the one that matters most is IFF1.

================================= HARDWARE ===================================

   At the hardware level, the Spectrum is a very simple machine. There's the
16K ROM which occupies the lowest part of the address space, and 48K of RAM
which fills up the rest. An ULA which reads the lowest 6912 bytes of RAM to
display the screen, and contains the logic for just one I/O port completes the
machine, from a software point of view at least.
Every even I/O address will address the ULA, but to avoid problems with other
I/O devices only port FE should be used. If this port is written to, bits have
the following meaning:

        Bit   7   6   5   4   3   2   1   0
            +-------------------------------+
            |   |   |   | E | M |   Border  |
            +-------------------------------+

The lowest three bits specify the border color; a zero in bit 3 activates the
MIC output, and a one in bit 4 activates the EAR output (which sounds the
internal speaker). The real Spectrum also activates the MIC when the ear is
written to. The upper three bits are unused.
If port FE is read from, the highest eight address lines are important too. A
zero on one of these lines selects a particular half-row of five keys:

      IN:    Reads keys (bit 0 to bit 4 inclusive)

      #FEFE  SHIFT, Z, X, C, V            #EFFE  0, 9, 8, 7, 6
      #FDFE  A, S, D, F, G                #DFFE  P, O, I, U, Y
      #FBFE  Q, W, E, R, T                #BFFE  ENTER, L, K, J, H
      #F7FE  1, 2, 3, 4, 5                #7FFE  SPACE, SYM SHFT, M, N,

A zero in one of the five lowest bits means that the corresponding key is
pressed. If more than one address line is made low, the result is the logical
AND of all single inputs, so a zero in a bit means that at least one of the
appropriate keys is pressed. For example, only if each of the five lowest bits
of the result from reading from port 00FE (for instance by XOR A/IN A,(FE)) is
one, no key is pressed. A final remark about the keyboard. It is connected in
a matrix-like fashion, with 8 rows of 5 columns, as is obvious from the above
remarks. Any two keys pressed simultaneously can be uniquely decoded by reading
from the IN ports. However, if more than two keys are pressed decoding may not
be uniquely possible.  For instance, if you press Caps shift, B and V, the
Spectrum will think also the Space key is pressed, and react by giving the
"Break into Program" report. Without this matrix behaviour Zynaps, for
instance, won't pause when you press 5,6,7,8 and 0 simultaneously.

Bit 5 (value 64) of IN-port FE is the ear input bit. When the line is silent,
its value is zero, except in the early Model 2 of the Spectrum, where it was
one. When there is a signal, this bit toggles. The Spectrum loading software is
not sensitive to the polarity of this bit (which it definitely should not be,
not only because of this model difference, but also because you cannot be sure
the tape recorder doesn't change the polarity of the signal recorded!). Some
old programs rely on the fact that bit 5 is always one (for instance Spinads).

Bits 6 and 7 are always one. The ULA with the lower 16K of RAM, and the
processor with the upper 32K RAM and 16K ROM are working independently of each
other. The data and address buses of the Z80 and the ULA are connected by
small resistors; normally, these do effectively decouple the buses. However, if
the Z80 wants to read of write the lower 16K, the ULA halts the processor if it
is busy reading, and after it's finished lets the processor access lower memory
through the resistors. A very fast, cheap and neat design indeed!

From Rui Ribeiro:
[If you read from a port that activates both the keyboard and a joystick port
(e.g. Kempston), the joystick takes priority. Every emulator except SpecEm
and WSpecEm get this wrong - see Street Hawk and Command4.]

If you run a program in the lower 16K of RAM, or read or write in that memory,
the processor is halted sometimes. This part of memory is therefore somewhat
slower than the upper 32K block. This is also the reason that you cannot write
a sound- or save-routine in lower memory; the timing won't be exact, and the
music will sound harsh. Also, INning from port FE will halt the processor,
because the ULA has to supply the result. Therefore, INning from port FE is a
tiny bit slower on average than INning from other ports; whilst normally an
IN A,(nn) instruction would take 11 T states, it takes 12.15 T states on
average if nn=FE. See below for more exact information.

If the processor reads from a non-existing IN port, for instance FF, the ULA
won't stop, but nothing will put anything on the data bus. Therefore, you'll
read a mixture of FF's (idle bus), and screen and ATTR data bytes (the latter
being very scarce, by the way). This will only happen when the ULA is reading
the screen memory, about 60% of the 1/50th second time slice in which a frame
is generated. The other 40% the ULA is building the border or generating a
vertical retrace. This behaviour is actually used in some programs, for
instance, in Arkanoid.

Finally, there is an interesting bug in the ULA which also has to do with this
split bus. After each instruction fetch cycle of the processor, the processor
puts the I-R register "pair" (not the 8 bit internal Instruction Register, but
the Interrupt and R registers) on the address bus. The lowest 7 bits, the R
register, are used for memory refresh. However, the ULA gets confused if I is
in the range 64-127, because it thinks the processor wants to read from lower
16K ram very, very often. The ULA can't cope with this read-frequency, and
regularly misses a screen byte.  Instead of the actual byte, the byte
previously read is used to build up the video signal.  The screen seems to be
filled with 'snow'; however, the Spectrum won't crash, and program will
continue to run normally.  There's one program I know of that uses this
to generate a nice effect: Vectron (which has very nice music too, by the way).

The processor has three interrupt modes, selected by the instructions IM 0,
IM 1 and IM 2. In mode 1, the processor simply executes an RST #38 instruction
if an interrupt is requested. This is the mode the Spectrum is normally in.

The other mode that is commonly used is IM 2. If an interrupt is requested,
egister (as
the high byte) with whatever the interrupting device places on the data bus.
The subroutine at this address is then called. Rodnay Zaks in his book
"Programming the Z80" states that only even bytes are allowed as low index
byte, but that isn't true. The normal Spectrum contains no hardware to place
a byte on the bus, and the bus will therefore always read FF (because the ULA
also doesn't read the screen if it generates an interrupt), so the resulting
index address is 256*I+255. However, some not-so-neat hardware devices put
things on the data bus when they shouldn't, so later programs didn't assume
the low index byte was FF. These programs contain a 257 byte table of equal
bytes starting at 256*I, and the interrupt routine is placed at an address
that is a multiple of 257. A useful but not so much used trick is to make the
table contain FF's (or use the ROM for this) and put a byte 18 hex, the opcode
for JR, at FFFF. The first byte of the ROM is a DI, F3 hex, so the JR will jump
to FFF4, where a long JP to the actual interrupt routine is put.

In interrupt mode 0, the processor executes the instruction that the
interrupting device places on the data bus. On a standard Spectrum this will be
the byte FF, coincidentally (...) the opcode for RST #38. But for the same
reasons as above, this is not really reliable.

The 50 Hz interrupt is synchronized with the video signal generation by the
ULA; both the interrupt and the video signal are generated by it. Many programs
use the interrupt to synchronize with the frame cycle. Some use it to generate
fantastic effects, such as full-screen characters, full-screen horizon
(Aquaplane) or pixel colour (Uridium for instance). Very many modern programs
use the fact that the screen is "written" (or "fired") to the CRT in a finite
time to do as much time-consuming screen calculations as possible without
causing character flickering: although the ULA has started displaying the
screen for this frame already, the electron beam will for a moment not "pass"
this or that part of the screen so it's safe to change something there. So the
exact time in the 1/50 second time-slice at which the screen is updated is
very important. Each line takes exactly 224 T states.

After an interrupt occurs, 64 line times pass before the byte 16384 is
displayed. At least the last 48 of these are actual border-lines. I could not
determine whether my monitor didn't display the others or whether it was in
vertical retrace, but luckily that's not really important.

From Ian Collier:
[This is probably not quite correct.  I have some exact figures, but so
far I have failed to bring them into the lab in order to program them
into xz80.  The 48K constants in there at the moment are wrong, but the +3
ones are correct.  On the +3 there are exactly 14368 (well, give or take 1)
cycles between the interrupt and byte 16384 being displayed, which turns out
to be 63 lines and 4 cycles. On the 48K it's 14339 cycles. *I think!*]

Then the 192 screen+border lines are displayed, followed by about 56 border
lines again. 56.5 border lines would make up exactly 70000 T states, 1/50th
of 3500000. However, I noticed that the frequency of the 50 Hz interrupt
(measured in 1/T states!) changes very slightly when my Spectrum gets hot
(I think it has something to do with the relative change of the frequencies
of the two crystals in the Spectrum), so the time between interrupts will
probably not be exactly 70000 T states.

From Ian Collier:
[This can't be true. A line contains exactly 224 cycles, and the screen
contains exactly 312 lines (on the +3 and other 128K machines, 311 lines of
228 T-states). If the screen didn't contain a whole number of lines then the
TV would not be able to display it correctly. This means that there are
exactly 69888 cycles in a frame. Unfortunately I have never determined whether
this means that the 50Hz clock is too quick or the 3.5MHz clock is too slow
(or neither, which would prove me wrong - note, though, that I have written a
program which depends on the correct number of cycles per frame).]

Anyway, whether the final border block is of fixed or variable length doesn't
concern us either, the timings of the start and end of the screen, which are
the timings of real interest, are fixed.

Now for the timings of each line itself. I define a screen line to start with
256 screen pixels, then border, then horizontal retrace, and then border again.
All this takes 224 T states. Every half T state a pixel is written to the CRT,
so if the ULA is reading bytes it does so each 4 T states (and then it reads
two: a screen and an ATTR byte). The border is 48 pixels wide at each side. A
video screen line is therefore timed as follows: 128 T states of screen, 24 T
states of right border, 48 T states of horizontal retrace and 24 T states of
left border.

When an interrupt occurs, the running instruction has to be completed first.
So the start of the interrupt is fixed relatively to the start of the frame
up to the length of the last instruction in T states. If the processor was
executing a HALT (which, according to the Z80 books I read, is effectively
many NOPs), the interrupt routine starts at most 3 T states away from the
start of the frame. Of course the processor also needs some T states to store
the program counter on the stack, read the interrupt vector and jump to the
routine. In interrupt modes 0, 0/1 and 1 the total time taken to get to
address 56 is 13 cycles. In interrupt mode 2 the time taken to get to the
interrupt routine is 19 cycles. Interpreted as follows:

  5 cycles: a read of the data bus (in IM 1 this is thrown away)
  6 cycles: a read of the 2-byte interrupt vector IM 2 only)
  8 cycles: to push the current PC and set the new one.

When an NMI occurs, the total time taken to get to address 102 is 15 cycles.
This is the same as for an ordinary interrupt but with two extra cycles
(reason unknown).

Now when to OUT to the border to change it at the place you want? First of
all, you cannot change the border within a "byte", an 8-pixel chunk. If we
forget about the screen for a moment, if you OUT to port FE after 14326 to
14329 T states (including the OUT) from the start of the IM 2 interrupt
routine, the border will change at exactly the position of byte 16384 of the
screen. The other positions can be computed by remembering that 8 pixels take
4 T states, and a line takes 224 T states. You would think that OUTing after
14322 to 14325 T states, the border would change at 8 pixels left of the upper
left corner of the screen. This is right for 14322, 14323 and 14324 T states,
but if you wait 14325 T states the ULA happens to be reading byte 16384 (or
22528, or both) and will halt the processor for a while, thereby making you
miss the 8 pixels. This exception happens again after 224 T states, and
again after 448, an so forth. These 192 exceptions left of the actual screen
rectangle are the only ones; similar things don't happen at the right edge
because the ULA don't need to read things there - it has just finished!
As noted above, reading or writing in low ram (or OUTing to the ULA) causes
the ULA to halt the processor. When and how much? The processor is halted each
time you want to access the ULA or low memory and the ULA is busy reading. Of
the 312.5 'lines' the ULA generates, only 192 contain actual screen pixels,
and the ULA will only read bytes during 128 of the 224 T states of each screen
line. But if it does, the processor is halted for exactly 4 T states.

=============================== INTERFACE 1 ==================================

   The Interface I is quite complicated. It uses three different I/O ports,
and contains logic to page and unpage an 8K ROM if new commands are used. The
ROM is paged if the processor executes the instruction at ROM address 0008 or
1708 hexadecimal, the error and close# routines. It is inactivated when the
Z80 executes the RET at address 0700.

a) Port E7:
   I/O port E7 is used to send or receive data to and from the microdrive.
Accessing this port will halt the Z80 until the Interface I has collected 8
bits from the microdrive head; therefore, it the microdrive motor isn't
running, or there is no formatted cartridge in the microdrive, the Spectrum
hangs. This is the famous 'IN 0 crash'.

b) Port EF:

       Bit    7   6    5    4    3    2    1     0
            +---------------------------------------+
        READ|   |   |    |busy| dtr |gap| sync|write|
            |   |   |    |    |     |   |     |prot.|
            |---+---+----+----+-----+---+-----+-----|
       WRITE|   |   |wait| cts|erase|r/w|comms|comms|
            |   |   |    |    |     |   | clk | data|
            +---------------------------------------+

Bits DTR and CTS are used by the RS232 interface.  The WAIT bit is used by the
Network to synchronise, GAP, SYNC, WR_PROT, ERASE, R/_W, COMMS CLK and COMMS
DATA are used by the microdrive system. If the microdrive is not being used,
the COMMS DATA output selects the function of bit 0 of out-port F7:


       Bit      7    6   5   4   3   2   1       0
            +------------------------------------------+
        READ|txdata|   |   |   |   |   |   |    net    |
            |      |   |   |   |   |   |   |   input   |
            |------+---+---+---+---+---+---+-----------|
       WRITE|      |   |   |   |   |   |   |net output/|
            |      |   |   |   |   |   |   |   rxdata  |
            +------------------------------------------+

TXDATA and RXDATA are the input and output of the RS232 port. COMMS DATA
determines whether bit 0 of F7 is output for the RS232 or the network.

============================ THE 128K SPECTRUMS ==============================

a) Memory

When memory is being paged, interrupts should be disabled and the stack should
be in an area which is not going to change. If normal interrupt code is to
run, then the system variable at 5B5Ch (23388) must be kept updated with the
last value sent to port 7FFDh. It is not possible to read this port.

On the 128 and +2, memory is entirely controlled by port 7FFDh. The byte to
output will be interpreted thus:

Bits 0-2: RAM page (0-7) to map into memory at 0C000h
Bit  3:   Select normal (0) or shadow (1) screen. The normal screen is in bank
          5 and normally appears at 4000h; the shadow screen is in bank 7 and
          can be switched in at 0C000h
Bit  4:   ROM select. ROM 0 is the 128k editor and menu system; ROM 1 contains
          48k BASIC.
Bit  5:   If set, memory paging will be disabled and further output to this
          port will be ignored until the computer is reset.

The memory map of these computers is:

FFFFh +--------+--------+--------+--------+--------+--------+--------+--------+
      | Bank 0 | Bank 1 | Bank 2 | Bank 3 | Bank 4 | Bank 5 | Bank 6 | Bank 7 |
      |        |        |(also at|        |        |(also at|        |        |
      |        |        | 8000h) |        |        | 4000h) |        |        |
      |        |        |        |        |        | screen |        | screen |
C000h +--------+--------+--------+--------+--------+--------+--------+--------+
      | Bank 2 |        Any one of these pages may be switched in.
      |        |
      |        |
      |        |
8000h +--------+
      | Bank 5 |
      |        |
      |        |
      | screen |
4000h +--------+--------+
      | ROM 0  | ROM 1  | Either ROM may be switched in.
      |        |        |
      |        |        |
      |        |        |
0000h +--------+--------+

Memory banks 4-7 are contended, i.e. the processor shares them with the ULA.
This reduces the speed of memory access in these banks.

b) Keypad

The 128K machine's keypad extra editing facilities are also available via
the normal keyboard:

                 FUNCTION                        KEYS
                 -----------------------------------------
                 Beginning of next word          [E] [S] J
                 Beginning of previous word      [E] I
                 Up ten lines                    [E] P
                 Down ten lines                  [S] I
                 Start of line                   [E] [S] 2
                 End of line                     [E] M
                 First line                      [E] N
                 Last line                       [E] T
                 Screen                          [E] [S] 8
                 Delete this character           [E] [S] K
                 Delete word left                [E] E
                 Delete word right               [E] W
                 Delete to start of line         [E] K
                 Delete to end of line           [E] J

                 [E] = Extended Mode
                 [S] = Symbol Shift

c) Sound Chip

The AY-3-8912 sound chip is a widely used one, to be found in the MSX,
Vectrex, Amstrad CPC range, etc. It is controlled by two I/O ports:

OUT (0FFFDh)   - Select a register 0-14
IN  (0FFFDh)   - Read the value of the selected register
OUT (0BFFDH)   - Write to the selected register

There's a guide to how to use the registers at

http://arachnid.cs.cf.ac.uk/User/K.E.W.Thacker/Amstrad/CPC_Guide/
Hardware_Programming/Chips/psg.html

 - this is for the CPC, so the I/O commands used will be different, and on the
Spectrum register 14 is used for the serial ports rather than the keyboard as
on the CPC.

******************************************************************************
********************************** PINOUTS ***********************************
******************************************************************************

1. ULA pinout

He *multiplexed* address-lines.

/WR   2    39 Q          One of the +5V is decoupled through a RC-low-pass.
/RD   3    38 /MREQ      U,V are the color-difference signals.
/WE   4    37 A15        /Y is the inverted video including sync.
A0    5    36 A14        D are the data-lines, decoupled from the CPU by
A1    6    35 /RAS       resistors.
A2    7    34 /ROM CS    T are the data-lines to the keyboard (address-lines
A3    8    33 /IO-ULA    through diodes).
A4    9    32 CLOCK      SOUND is the analog-I/O-line for beep, save and load.
A5   10    31 D7         CLK is the clock-source to the CPU including the
A6   11    30 D6         inhibited T-states.
/INT 12    29 D5         IO-ULA is (A0(CPU) OR /IORQ) for the I/O-port FEh
+5V  13    28 SOUND      Q is the 14MHz-crystal, other side grounded through
+5V  14    27 D4         a capacitor
U    15    26 T4
V    16    25 D3
/Y   17    24 T3
D0   18    23 T2
T0   19    22 D2
T1   20    21 D1

2. AY-3-8912

SOUND C   1    28  D0       Vcc is +5V.
PORT      2    27  D1       SOUND A, B and C can be tied together.
Vcc       3    26  D2       CLOCK can be some MHz.
SOUND B   4    25  D3
SOUND A   5    24  D4
GND       6    23  D5
PORT      7    22  D6
PORT      8    21  D7
PORT      9    20  BC1
PORT     10    19  BC2
PORT     11    18  BDIR
PORT     12    17  A8
PORT     13    16  RESET
CLOCK    14    15  CLOCK

3. Keyboard layout

  OUTER SIDE   A 15 14 8  13 12 9  10 11  INNER SIDE
             D
             0   BR EN CS P  0  A  Q  1
             1   SS L  Z  O  9  S  W  2
             2   M  K  X  I  8  D  E  3
             3   N  J  C  U  7  F  R  4
             4   B  H  V  Y  6  G  T  5
  INNER SIDE

  [BR] BREAK   [EN] ENTER   [CS] CAPS SHIFT   [SS] SYMBOL SHIFT

  In real the matrix connections are in one row on the top side of
  the membrane.


******************************************************************************
******************************* ACKNOWLEDGEMENTS *****************************
******************************************************************************

Thanks to:

  Richard Carlsson   - for info on his Speccylator emulator for the Amiga.
  Ian Collier        - xz80 emulator, advice, Z80 information and more...
  Krzysztof Czysciak - information about Elwro emulator.
  John Elliott       - information about 128K machines.
  Marat Fayzullin    - for creating FAQ versions before 2.7!
  Arnt Gulbrandsen   - for keeping Spectrum WWW page, FTP archive and multiple
                       contributions to this file. Also, for his IBM PC-based
                       JPP emulator. Your WWW page *is* cool, Arnt. ;)
  Simos Hadjiyiannis - for several FTP addresses I didn't have.
  Martijn van der Heide - for his database program and Jeroen Kwast's new
                       email address.
  Des Herriott       - for his xzx emulator, which is the first and the only
                       way to play LodeRunner on a Unix workstation! :)
                       (ignoring the unix version of course - eh Ian?)
  A.G.Jackson        - information about emulators for Acorn Archimedes.
  Bob Johnson        - information about TS2068 and TK90X.
  Gerton Lunter      - for the excellent information about ZX-Spectrum
                       internals and Z80 emulator for IBM PC.
  Peter McGavin      - for some useful information and (of course =:)) his
                       excellent Spectrum emulator which actually *multitasks*
                       under AmigaDOS and is system-friendlier than many other
                       programs.
  Miguel Melo        - information about several programmers.
  Alexander Mudretsov- information about the SP105 emulator.
  Joseph S. Myers    - information on undocumented Z80 behaviour.
  Troels Norgaard    - information about KGB.
  Emil Obermayr      - for pinouts of ULA, AY-3-8912 and keyboard layout.
  Boudewijn Rempt    - compilation of postings for "WHERE IS...?"
  Rui Ribeiro        - for several contributions to "TECHNICAL INFORMATION",
                       and WSpecem.
  Jon Ritman         - information about himself!
  Adam Roach         - maintainer of comp.emulators.misc FAQ; information
                       about the Speccy BASIC emulator for the C64.
  Thorsten Roskowetz - information about Atari-based emulator.
  Marcelo Strasunas  - information about TK90X and TK95.
  Stephen Smith      - information about several programmers and his great
                       games FAQ and database web pages.

... and everybody else who has contributed to the FAQ, manages FTP archives,
writes Speccy emulators and generally helps to keep the Speccy alive!