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- Documentation for Arc100 Beta-Test 2.2 - a PD VT100 Terminal Emulator
- ---------------------------------------------------------------------
-
- All code and documentation is the exclusive copyright of Richard K. Lloyd,
- but it may be freely distributed and is completely in the Public Domain.
-
- ATTENTION !
-
- Although this program has (finally) been released into the Public Domain,
- it is strictly beta-test and may contain some minor flaws. The author accepts
- no responsibility if these flaws cause any problems for the user whatsoever.
- Please report any problems/bugs to the address at the end of this document -
- XON/XOFF at high baud rates is suspect at the moment...apologies for this.
-
- Introduction
- ------------
-
- Arc100 is a VT100 terminal emulator I wrote a while ago and never released
- into the PD because RISC OS caused it to stop handling XON-XOFF correctly.
- I finally corrected this during the Christmas 1990 break - I tracked it down
- to the event vector routine I had written taking too long to flash the custom
- cursor :-)
-
- Supplied Features of Arc100
- ---------------------------
-
- * Complete custom character set (8 by 10 pixels) 'turbo-poked' onto the screen
- * Intelligent buffering - does not display characters until there is a break
- in the transmission or a cursor movement occurs
- * On-screen clock showing current time or elapsed connect time
- * 132-column mode (SET TERM/WIDTH=132 in VAX/VMS performs a spectacular mode
- change - most other VT100 emulators simply clear the screen)
- * Four speeds of scrolling (1,2,5 or 10 pixels at a time)
- * Double-height/double-width characters
- * Knows all the 'funnies' used by full-screen editors such as VAX/VMS's EDT
- * Custom variable-width cursor
- * Point-and-click with the mouse to move the cursor
- * Individual tab setting allowed
- * Custom dialogue box system - auto-scales in 132-column mode
- * Exit to the Desktop and re-entry into the emulator by clicking on its icon
- again returns to it in exactly the same state as it was left
-
- How to Use Arc100
- -----------------
-
- The application installs an icon bar icon when double-clicked. This simply
- has the standard Info and Quit options and needs no further explanation.
- Clicking on the icon bar icon with the left or right buttons will enter the
- emulator (or re-enter where you left it). Arc100 takes over the whole screen
- in MODE 12 (or MODE 16 for 132-column mode) and hence I did not bother
- making the code multi-tasking. The other reason is because high-speed on-screen
- poking is performed for most operations - this is infeasible with windowed
- multi-tasking programs.
-
- The status line at the bottom of the screen ("Line 25") displays the following:
-
- * Four LEDs simulating VT100 LEDs 1 to 4. Clicking on them will toggle their
- status, as will sending the appropriate escape sequence.
-
- * VT100/VT52 mode indicator. Clicking on this will toggle between VT100 and
- VT52 emulation.
-
- * Online/Local indicator. Again, click to toggle. "Online" mode means that the
- host must generate characters to be displayed, whereas "Local" means that
- you may type locally and the characters are displayed and not sent to the
- host (and any characters generated by the host are ignored). "Local" mode
- is very useful for testing certain escape sequences (try ESC # 8).
-
- * Cursor X,Y position. Can be handy in some circumstances (especially dreaded
- IBM mainframes !).
-
- * Setup. Clicking on this will bring up a very self-explanatory dialogue box
- (Setup 1) with options in it to jump to further boxes (Setup 2 and Setup 3).
-
- * Reset. Clicking on this will reset the terminal to the settings immediately
- after the last save or load of the setup file. Unlike some other terminal
- emulators, this does NOT involve a re-load of the settings from disk.
-
- * Exit. Clicking on this will return you to the Desktop, BUT you can return
- to exactly the same position (including intact screen text) by simply
- clicking on the icon bar icon again.
-
- * Program version string. Click on this for a version dialogue box containing
- RS423 transmit/receive figures too. This facility is omitted (due to lack
- of space) in the 132 column mode.
-
- * Clock. Can display nothing at all, the current time or the elapsed connect
- time (the later can be reset by simply clicking on the timer).
-
- Saving the Setup
- ----------------
-
- There is an option in the Setup 1 dialogue box to load the setup and also an
- option in Setup 2 to save it. Please note that the setup will NOT be loaded
- when Arc100 is first run and installed on the icon bar. It only loads when
- the icon bar icon is clicked on for the very first time, so floppy users
- should not remove the disk with Arc100 on until the icon bar icon has been
- clicked on to enter the emulator. You may add a saved setup filename to the
- end of the execution line in the !Run (the default is <Arc100$Dir>.!TermSetup),
- but Arc100 does not have its own filetype for these setup files. You may
- execute the !RunImage binary with a -help qualifier to get a page of slightly
- useful information.
-
- Other Special Bits
- ------------------
-
- The numeric keypad acts identically to a VT100 keypad. Num Lock / * and #
- behave as PF1 to PF4 (as do, incidentally, the function keys f1 to f4).
- Break on its own sends a short break, whereas Alt-Break sends a long one.
- Home locally homes the cursor and Shift-Home locally clears the screen as
- well as homing the cursor.
-
- IntelliMouse System
- -------------------
-
- This is an intuitive method of moving the cursor (in Online or Local mode)
- using the cursor keys or the mouse. If the mouse is clicked on a character
- cell, then the cursor will move to that position (or directly in Local mode).
- It does this by sending up/down sequences to the host first (and abandoning
- this if the cursor never reaches that line - some editors have a scrolling area
- which defeats this) and then left/right sequences afterwards. The cursor keys
- also have their intuitive meanings: Shift-Left or Shift-Right skip to the end
- of the word and Ctrl-Left or Ctrl-Right go to the appropriate edge of the line.
-
- Technical Section
- -----------------
-
- Arc100 is written ENTIRELY in ARM code and has been 'file-protected' to avoid
- tampering. The source code exceeds 250K and has not been supplied with this
- PD release. I used a Plessey PT100 (plus the manual) to test out my theories
- to the limit - the PD 'vttest' C program was also quite a help.
-
- No, I'm not stupid enough to use a second screen buffer to save the screen
- between invocations - the character plotting routines are quick enough to
- allow redraw from a character grid in memory. The whole application needs only
- a 48K WimpSlot (plus 136K screen space of course for MODEs 12 and 16).
-
- Known Problems with Arc100 Beta-Test 2.2
- ----------------------------------------
-
- * When the cursor is over a bold character, the character should be visible
- in some form of reverse video, but the palette messes this up and the
- character becomes almost invisible...
-
- * XON-XOFF code rehash has not been fully tested yet - may be suspect under
- extreme circumstances.
-
- Missing Features of Arc100 Beta-Test 2.2
- ----------------------------------------
-
- * New RISC OS baud rates (e.g. 110 baud). Should really allow receive and
- transmit rates to be set separately.
-
- * File transfer protocols. Should permit ASCII transfer at the very least.
-
- * Printer support. I'm sceptical about this because most people would probably
- prefer to transfer the files up (and print them on the host) or down (and
- print them on the Archimedes). Besides, have you ever seen a printer that
- does a full VT100 emulation ? :-) Better would be a simple session logging
- facility.
-
- * Tektronix graphics. Also sceptical here, but if enough people demand it, then
- I might consider it.
-
- * Multi-tasking support. Fat chance of this considering the design of
- the program. There's no way I'm sacrificing the speed of the emulator :-)
-
- * OSCLI support. An easy one to add, but one open to abuse (e.g. running
- new applications or, even worse, memory editors).
-
- Revision History
- ----------------
-
- Beta-Test Releases
- ------------------
-
- Version 2.2 (January 1991)
-
- First PD release, but not 100% perfect yet. I've been at the code for
- over 2 years now (on-and-off of course) and it's about my biggest
- project ever. XON-XOFF still unstable. Plenty of code tweaks everywhere.
- Fixed function key problem (wasn't restoring properly on exit to Desktop)
- and also made the Desktop exit/re-entry smoother (only changes MODE if
- it has to).
-
- Version 2.1 (December 1989)
-
- Worked prior to RISC OS, but RISC OS's XON-XOFF support doesn't like long
- event routines (mine flashed a cursor), so this version dropped more
- characters than an episode of Dallas :-) Added RISC OS support in the form
- of an Info Window and menu, plus the ability to exit and re-enter the
- emulator exactly as you left it.
-
- Version 2.0 (mid-1989)
-
- Added an incredibly fast section to the character output routine. If a
- completely plain character is plotted, then pre-expanded characters are
- blitted straight onto the screen - providing a 4-fold increase in speed !
-
- Version 1.0 (mid-1988)
-
- Sick to death with the lack of a DECENT VT100 terminal emulator for use
- with VAX/VMS, so slaved for a solid month to get an Arthur 1.20 version
- of Arc100 working. Just a straightforward Absolute application with pretty
- characters (understatement of the year there !).
-
- Where to report bugs or suggest enhancements
- --------------------------------------------
-
- Sorry to hog the source code to myself, but it's been my baby for a long, long
- time and I'm not ready to put it up for adoption (or should that be adaption ?)
- yet :-) Maybe sometime in the future when it stabilises (1995 ?).
-
- Post Office Mail: Richard K. Lloyd, JANET e-mail: rkl@uk.ac.liv.cs.and
- 1, Banks Road,
- Lower Heswall,
- Wirral,
- Merseyside.
- L60 9JS
-