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- ; History:
- ; The first versions of CPE were developed on a Commodore Amiga 500, 7MHz.
- ; They were quite slow! I converted it to Intel assembler after I bought a PC
- ; in June 93. I derived some ideas for the Z80 emulation from a public domain
- ; CP/M emulator by Charlie Gibbs called SIMCPM for the Amiga. I had to rewrite
- ; it completely since it supported neither banking nor interrupts. The only
- ; remains of SimCPM are some labels in the Z80 section and the opcode tables.
- ;
- ; v0.0: 910602 Basic emulation of z80 instructions
- ; Some emulation of CPC's Mode 1 is done (SLOOOOOOW!)
- ; v0.1: 910605 Added some I/O support
- ; v0.2: 910607 increased speed about 10 times, but it's still slow
- ; probably the best way to speed the whole thing up
- ; is a 68040 board
- ; v0.3: 920504 fixed bug in GA memory management, so upper rom is called
- ; now; added primitive interrupts (every 1000 Z80 instructions)
- ; v0.4: 920505 keyboard emulation added; exit now possible with both ALT keys
- ; v0.5: 920506 fixed bugs in Z80 XOR A, SBC and ADC commands; frame fly
- ; interrupts; keymap (there were two Z keys)
- ; most OS and BASIC functions are now working properly
- ; added colors and video mode 2 support
- ; still not working: scrolling, floating point arithmetics
- ; v0.6: 920507 completely rewrote code for Z80 DAA and ADD,SUB,SBC,ADC
- ; instructions. Result: BASIC arithmetics are now working
- ; almost correctly, but occasionally there are still some
- ; problems. Added scrolling (sloooooow!)
- ; v0.7: 920509 now supporting multiple roms; added rom 7 (floppy control)
- ; no floppy hardware emulation right now
- ; added some optimizations
- ; v0.8: 920512 implemented floppy emulation by redirecting subroutines in
- ; the CPC's floppy ROM to 68000 code. Except formatting, all
- ; major disk operations are emulated. The file DriveA.dat
- ; contains the data of the emulated CPC drive. CP/M can be
- ; started and will work properly (I tested it with
- ; INFOCOM's ENCHANTER). Currently only standard disk formats
- ; (9 secs/track, 512 bytes/sec) are emulated
- ; v1.0: 920513 implemented video mode 0. In this version, all major functions
- ; of the CPC should be working (I didn't test all of them,
- ; though).
- ; on startup not only the current directory is checked for ROM
- ; files, but also a volume called "CPemul:"
- ; v1.1: 920515 found two bugs in Z80 simulation code, a minor one
- ; in the LD (HL),H instruction and a rather nasty one which
- ; prevented the DAA command from working when a PUSH/POP AF
- ; occurred before it. Since the 68000 does not implement BCD
- ; arithmetics by a halfcarry and an add/subtract indicator, but
- ; has instructions for adding and subtracting BCD bytes, a Z80
- ; emulator has to find a workaround. This is done by saving
- ; both operands of each add operation. When a DAA occurs, these
- ; operands are restored and added with the 68000 Add BCD command
- ; The result is written in the accumulator. This is fine as long
- ; as there is nothing like PUSH AF/ADD A,C/POP AF in the code.
- ; But exactly this happens when an interrupt occurs between the
- ; ADD and the DAA commands. Solution in this version: have an
- ; extra stack for the BCD operands. The number of errors has
- ; been reduced, but there are still occasional errors.
- ; Improved interrupt emulation, TETRIS now works.
- ; CRTC emulation now supports variable screen widths
- ; added primitive form of Z80 debugging (regs printout)
- ; v1.2: 920517 almost complete Z80 disassembler (except DDs&FDs)
- ; simple Z80 singlestep debugger implemented
- ; v1.25: 920519 fixed bug in debugger's (f)orward command, added (z)ip
- ; added (c)olor mode command
- ; v1.3: 920521 more bugs fixed in cpe2.asm; RR (HL) didn't write back
- ; (HL) contents after the operation. The M flag is now set
- ; correctly after a BIT instruction (even Z80 experts may be
- ; surprised to learn that this flag should be set although
- ; even the official Z80 documentation says the flag contents is
- ; unknown after BIT. I didn't find out until some program used
- ; a JP M,xxxx after a BIT 7,(HL) instruction). The result of
- ; all this: the game "The Sentinel" now displays 3D gfx
- ; correctly.
- ; also new this version: mode 0 scrolling without ugly stripes,
- ; better emulation of IN instruction, undocumented opcodes
- ; DD/FD 67/6F
- ; v1.4: 920527 found out why ELITE was crashing: the time between
- ; interrupts was too small.
- ; Fixed some more bugs: EX (SP),IX / EX (SP),IY
- ; increased speed of LDIR instruction, added debugger commands
- ; i1-i3 (interrupt speeds, for ELITE mainly)
- ; v1.5: 920529 fixed bug in calcind macro, which was responsible for the
- ; errors in Turbo Pascal numeric output (offsets to IX were
- ; always positive, although 80..FF must be interpreted as
- ; negative numbers. This one may have been left over from SIMCPM.
- ; I am not sure though, and can't find out since I deleted the
- ; SIMCPM files
- ; added debugger 'm' command
- ; v1.6: 920602 'm' command now working correctly
- ; corrected bugs in keymap, added joystick emulation
- ; did some research on the floppy controller IO addresses
- ; FA7E/FB7E/FB7F. I think I have quite a good idea about what
- ; is happening when the floppy rom accesses those addresses.
- ; v1.7: 920603 implemented some elements of floppy emulation; some rom7
- ; routines no longer have to be replaced by special 68000
- ; routines. Hardware emulation for track selection and sector
- ; ID information now replaces old 68000 routines
- ; v1.8: 920604 implemented floppy controller $46/$66 commands
- ; v1.9: 920609 implemented Z80 (R)efresh register. It is used by some games
- ; as an instruction counter for decoding parts of their
- ; memory. "Certain games" means Bard's Tale, which nevertheless
- ; does not feel like working right now.
- ; Also fixed a bug in OUT (C),D --> Starglider now
- ; displays gfx correctly
- ; v1.9b: 921019 now Kickstart 2.0 compatible (how could I mess up OpenWindow
- ; like that !?!)
- ; v2.0: 950212 RELEASED
- ; changed volume name from CPEmul: to CPE:
- ; commented out the 68000 native emulation parts, because they
- ; only work for 664 ROMs.
- ; v2.0a: 950219 made a 680x0 version, for x >= 1. Also new: a small utility
- ; to convert .DSK files to the old .DAT format
- ; Oops, there seems to be a bug left in the Z80 emulation.
- ; 'Labyrinth' from CPCPD1.DSK doesn't work as it should.
- ;
- ; ***************************************************************************
- ;
- ; v2.00: 930926 first version for IBM-AT and "100% compatible"...
- ; first version that is working at least a bit, that is.
- ; Some mode 1 support, colors work, no floppy disk emulation
- ; Strange behaviour though from the emulated keyboard (in fact,
- ; it is not emulated, but produces characters anyway...)
- ; This is my first program in 80386 assembler which is longer
- ; than ten lines.
- ; v2.01: 930927 another bug bites the dust - in fact, hundreds of them!
- ; the result: working support of all cpc gfx modes
- ; (incl. scrolling & weird modes & colors & blinking)
- ; working keyboard emulation (PC/XT compatible keyboard)
- ; other hardware requirements: VGA, 80386
- ; trouble with BASIC's NEXT command (FPO stuff)
- ; v2.05: 930928 fixed bugs in (BIT 2,whatever) --> no trouble with testing
- ; the ESC key. Also fixed: flags were often killed when AX
- ; had to be PUSHed to do an operation (DD/FD adds...)
- ; v2.10: 931027 floppy load is now emulated. Elite & Tetris work!
- ; complete crash for Bard's Tale, though
- ; Starglider: same problem as on the Amiga
- ; v2.11: 931028 corrected some flag settings --> correct hex output from
- ; BASIC
- ; v2.12: 931225 more bug corrections: better R register implementation, so
- ; Bard's Tale now loads
- ; no problem now when screen width is set to 0, so Bard's Tale
- ; no longer crashes immediately after loading - it WORKS!!!!
- ; multiple sector read now works (BT did not even get to the
- ; R register part on the INTeL version until now)
- ; DD6F/DD67 were reversed - that was Starglider's problem.
- ; Now gfx were displayed.. until the machine crashed: I had
- ; forgotten a POP CX in DD22/FD22... oops. Starglider now works!
- ; something incredible happened: I had nowhere in the INTeL version
- ; used the dozmf macro for BIT 7 instructions, but Sentinel showed
- ; its gfx correctly nevertheless, I have no idea why it failed
- ; to do so on the Amiga version. And I have no idea why it keeps
- ; saying "wrong secret code" (aarggh)!
- ; v2.2: 940206 Received Marco Vieth's emulator two days ago. Amazed by the
- ; speed of his screen refresh I realized that there must be a
- ; faster method than the one I used, so I improved my routines quite
- ; a bit. I no longer have three separate routines for screen refresh,
- ; but only one universal routine which handles all modes and is
- ; significantly faster than the old three ones.
- ; ldir has been sped up quite a bit (same method as in Amiga version)
- ; poor lddr is still the same...
- ; v2.21: 940207 FINALLY!! I have found the bug which caused Sentinel to fail...
- ; it was, as usual, one wrong character: "gbhl AX" instead of
- ; "gbhl AL" in CB16. It Is NoW wOrKiNg!!!
- ; v2.3: 940209 implemented better interrupt emulation. Interrupts are now called
- ; almost precisely 300 times a second. Problem: LDIR, LDDR and
- ; other time-consuming operations may delay an interrupt. I may
- ; have to use another routine in the future. Currently I use
- ; BIOS interrupt 15h, function 83h
- ; v2.4: 940213 G.A.Lunter's documentation to his ZX Spectrum emulator helped
- ; me find 8 missing opcodes in my code: CB30..CB37 (SLL A..(HL))
- ; Gigacad now works. Implemented sector save by bypassing rom 7
- ; code
- ; v2.41: 940214 corrected HALT which did not work with the new interrupt model
- ; better emulation of 8255, so AIRBALLS now works - but no overscan :-(
- ; At least, the keyboard interrupt now works as it should - and
- ; it was about time! Also: slightly faster screen refresh
- ; v2.42: 940220 many little optimizations resulting in a nice speed increase:
- ; ELITE now works at normal interrupt frequency
- ; Screen redraw routines have been improved: they are a lot faster
- ; now and more friendly to the eye (the pointer to the PC screen
- ; is now used as loop variable, so screen is refreshed from top
- ; to bottom instead of »draw the first line of all characters...«)
- ; Disk write corrected (working again!). None of my programs
- ; have any difficulties now. Problems though with MV's disk:
- ; I suspect he uses RAM-Banking, which I have not implemented
- ; Almost nothing from this disk works!
- ; v2.43: 940221 fixed a bug that was introduced in the last version: screen
- ; width 40 height 0 crashed the machine (a table of 256 lines was
- ; generated instead of one with no lines)
- ; v2.5: 940223 OVERSCAN! Muri & Airballs now display their full screens!
- ; better interrupt emulation (now 292 ints/sec instead of 256)
- ; The problem is the PC's RTC which can only generate interrupt
- ; frequencies like 1024 or 2048Hz etc.
- ; v2.6: 940225 this version implements what I have always dreamed of: colored
- ; stripes! I am incredibly happy with these, even if they don't
- ; always start at the exact line. In fact, there is a lot of
- ; room for improvements, but the most important thing is that
- ; ELITE now has correctly colored zones.
- ; v2.7: 940303 This version introduces double buffering support - AIRBALLS
- ; is significantly faster than on an older version. Everything
- ; else works as usual, only Starglider did not like the change
- ; and crashes a bit more often - but I am used to having nothing
- ; but trouble with this program.
- ; v2.71: 940312 implemented diskchange feature and corrected some bugs.
- ; most of MVs programs now work, DD7D changed F instead of A!
- ; v2.8: 940317 this version uses the timer instead of the RTC and has the
- ; correct interrupt speed of 300.4Hz, exactly the same screen
- ; refresh rate in PCRTC mode 2 and thus better color stripes.
- ; v2.9: 940320 many little speedups and a major one: R emulation can now
- ; be switched off via a different opcode table. Not quite enough
- ; for troublemaker Starglider though, it still has to run with
- ; half the interrupt speed.
- ; implemented a nice little menu to control various aspects of
- ; the emulation: R register, FF synchronization, double buffering,
- ; interrupt omission, ffly bit reset
- ; v2.91: 940331 corrected the bug in scroll routines, it is now possible to use
- ; 8 bit access instead of 16 bit. Screen widths up to 255 no longer
- ; crash both CPC and PC. FDC emulation improved, no crashes after
- ; diskchanges any more
- ; v2.92: 940401 corrected bug in RR (IX+d); better emulation of illegal FDs;
- ; FDC can now write without patch. Cassette emulation! Loads
- ; from the DOS directory TAPE\. Can't write and is quite slow
- ; v2.93: 940402 corrected some in/out bugs, so the 'Last Demo' now works.
- ; patched CAS IN OPEN to speed up the process
- ; v3.0: 940403 SOUND! quality ranges from very good (TETRIS) to poor
- ; (everything which uses noise generator). Makes ELITE crash,
- ; probably too slow.
- ; v3.01: 940404 corrected bug: huge overscan screens became very small, because
- ; the VGA card did not get a MSB. Now FULLSCR and Sounddemo work
- ; better.
- ; v3.1: 940414 some slight speedups; some obsolete code removed
- ; more undocumented DDCBs, IM2 implemented for Boulder Dash (works!)
- ; Also a little RAM-banking (in a very early stage: incorrect
- ; screen refresh, slow)
- ; v3.11: 940415 faster scrolling by moving VGA screenstart, emulation is slowed
- ; down a bit though. New also: INI, OUTI, OUTD, IND
- ; v3.12: 940416 added feature to CAS IN OPEN, spaces in names are now deleted
- ; when necessary. Also corrected CAS IN OPEN patch in 6128 ROM
- ; increased scrolling speed by faster offset table generation
- ; v3.2: 940420 new in this version: multimode. It works... sometimes. There
- ; is still a lot of room for improvements. Better joystick
- ; emulation for Devil's Crown, which crashes when the emulated
- ; joystick is simultaneously pushed left and right.
- ; v3.3: 940422 improved SetPCsCRTC, which now no longer interferes with the
- ; timer interrupt, so that the picture is restored without
- ; trouble in displaymode 2. CPE can now load snapshot files
- ; in Marco Vieth's format. Corrected a huge bug in RethinkRAMState
- ; (ES was not saved, I wonder why it worked at all until now!)
- ; There was an error in my hardware documentation concerning the
- ; 8255 control register; this is now fixed. Caps and Num Lock
- ; LEDs are controlled by the keyboard interrupt. Speed has been
- ; increased quite a bit by replacing the JMP simz80l at the end
- ; of each instruction by a short sequence which either jumps to
- ; the next opcode or to the »interrupt and other stuff« handler
- ; v3.31: 940423 better port emulation; as on a real CPC you can now address
- ; several chips with one OUT. I hardly think that anyone ever
- ; used that feature, though. Corrected a HUGE bug in LDD: it
- ; did not set the flag register, it changed the accumulator.
- ; Oooops! Wonderboy now works. Also improved FDC emulation,
- ; »@« now works.
- ; v4.0: 940426 Yes, that's version FOUR, although there have only been two
- ; bug corrections since version 3.31, but these were *HUGE* bugs,
- ; which had been in CPE since the beginning.
- ; Rule No.1: Never be sure that the stack segment is always the
- ; same in your interrupts. DOS functions may modify SS, so you
- ; get nice crashes when your interrupt is called while DOS is
- ; active and you try to reach your data via the BP register
- ; (ASSUMEd: SS=DS=DATA). This bug caused lots of trouble and
- ; was incredibly hard to find.
- ; The second bug only crashed the CPC: I never knew that when
- ; an interrupt occurred, all further interrupts were disabled.
- ; Hardly any program depends on this, since they do a DI command
- ; anyway at the start of the interrupt routine, but Hardball and
- ; Overlander crashed in the old version.
- ; So much for bug hunting!
- ; v4.1: 940501 corrected bugs in multimodes, almost all programs now work
- ; EMS can be used to emulate RAM banking. CP/M Plus does not
- ; work very well, though.
- ; v4.11: 940507 printer support
- ; v4.2: 940514 new diskfile format, diskfiles can now be crunched. Minor
- ; bugs removed
- ; v4.3: 940522 corrected bugs in PIO: Antiriad and Barbarian now work.
- ; multimodes are a little more stable when there are changes in
- ; one frame caused by timing problems. Corrected R emulation,
- ; Mission Elevator now works
- ; v4.4: 940605 new: packed tape archives
- ; v4.5: 940707 realtime cpc (more or less), compatibility to other graphics
- ; cards than OAK.
- ; v4.6: 950223 enhanced compatibility to CPCEMU: CPE can now read V2
- ; snapshots, .DSK files and CPCEMU style ROM files.
- ; .DSK file support is currently write protected.
- ; made a second version that uses 256 color 320x256 mode, runs
- ; realtime and has almost perfect color/multimode emulation.
- ; fixed the 'clear interrupt' feature of the Gate Array
- ; v4.7: 950308 Bug fixes. Enhanced joystick support. Refresh rate for CPE2
- ; can now be configured in CPESETUP
- ; v4.8: 950802 Added Ulrich's GUS support. Included the ROMs and STRIPES.BAS.
- ; v4.81: 950825 Made CPE2.EXE handle overscan screens better. Horizontal
- ; scrolling is possible with the F11/F12 keys.
- ; Cleaned up CPESETUP. New option to disable cassette messages
- ; by patching the ROM.
- ; New menu option in CPE2 to force a display height of 200
- ; lines.
- ; v4.82: 950826 cleaned up the screen part in CPE2. Better display for
- ; many programs. Beginnings of an emulation for the 'split
- ; screen' or 'rupture' technique (quite buggy yet).
- ; v4.83: 950828 fixed a bug in OUT decoding.
- ; v4.84: 950829 fudged the FDC emulation to get Logon's "The Demo" working.
- ; Finally found the bug in the EMS part in CPE2.EXE: The
- ; documentation (Data Becker...) had a DI where a SI was needed.
- ; v4.85: 950830 moved some more common code into top directory.
- ; It should no longer be possible to crash CPE with an
- ; uncalibrated joystick.
- ; Cleaned up the menus a little.
- ; v4.86: 950831 Re-enabled VESA mode support in CPE2. It's possible to use
- ; a 800x600x256 screen. Borders can be enabled in the menu.
- ; v4.87: 950901 Menus can now be painted on the CPC screen instead of
- ; switching back to a text mode. This saves some pain for the
- ; monitor. (Only implemented in CPE2)
- ; Changed a few bits and pieces in the CRTC emulation (in CPE2)
- ; The Voyage 93 Demo now identifies the CRTC as type 2 (used to
- ; be type 1). Some programs work better, others have new
- ; problems :-/ The "Advanced" Demo now works.
- ; v4.88: 950902 Implemented the CRTC's 32K screen size feature (seems to
- ; work). Only for CPE2, 800x600, EMS.
- ; Centering now works in 800x600 with borders.
- ; Returned to CRTC type 1, because type 2 breaks some programs,
- ; although I believe it is the Right Thing to use type 2. The
- ; choice can now be made at compile time.
- ; v4.89: 950905 Finally wrote a better snapshot filename prompting routine.
- ; A list of files is shown, and the filename you type can be
- ; edited.
- ; When you select a diskfile or a snapshot, the next time you
- ; enter the menu again the pointer will be on the last file you
- ; selected.
- ; Apparently, when an interrupt occurs, the next interrupt can
- ; happen only after 52 further scan lines. Changed CPE2
- ; accordingly (and what I have to do in ResetInterruptCounter
- ; finally makes sense)
- ; v4.9: 950908 Hmm... now I can make Voyage 93 detect a CRTC 0, but no longer
- ; a CRTC 2 - the "CRTC 2" setting now produces type 1 as well.
- ; But the "CRTC 2" setting seems to work best, so I think I'll
- ; leave it at that.
- ; Fixed interrupt behaviour - at least, a little test program
- ; gives the same results now as on the real CPC. However, "real"
- ; programs are sometimes not quite as happy about the change
- ; v4.91: 950909 Fixed a few problems with CRTC emulation. Many parts of "The
- ; Demo" or "Voyage 93" now work fine.
- ; v4.92: 950910 Fixed some more problems with the CRTC. Most demos now work
- ; great, with some little problems occasionally.
- ; Finally figured out how to pretend the different CRTC types
- ; correctly:
- ; CRTC 0: Short frame fly interval ( <9 scanlines)
- ; CRTC 1: Long frame fly interval ( 17 scanlines?)
- ; CRTC 2: Like CRTC 1, but buggy: No frame fly generated when
- ; screen width is 50.
- ; Reordered most of the main loop to clean things up.
- ; v4.93: 950911 Made 32k screens possible in "small VESA mode".
- ; In the menus, you can jump to a specific diskfile group by
- ; pressing the first letter from the name.
- ; Fixed a stupid bug in the CPE2 320x200 scrolling routines.
- ; v4.94: 950913 Improved interrupt generation. Some programs work again, and
- ; my little "INTTEST.BAS" gives correct answers in all tested
- ; cases. However, the "Turn Disk" part of The Demo and some
- ; other stuff is broken now :-{
- ; v5.00: 950914 Some more correct answers from INTTEST, and the Face Hugger
- ; demo seems to work all the way. "Turn Disk" from The Demo is
- ; still broken, but apparently nothing else.
- ; v5.01: 951005 Fixed the "Clear Interrupt Counter" feature - it's only
- ; supposed to clear the high bit.
- ; Fixed some extremely silly bugs in the 8255 emulation. This
- ; should really work now.
- ; Removed the 'R emulation' setting from CPE2, it's pointless
- ; for fast machines that CPE2 is supposed to run on.
- ; Implemented automatic refresh rate calculation for CPE2. If
- ; the PC is too slow, no screen will ever be drawn.
- ; v5.02: 951006 Attempt to implement directory changing for the disk
- ; selection menu. Crashes sometimes.
- ; v5.03: 960204 New GUS code from Ulrich. Trying to fix directory changing.
- ; v5.04: 960418 New FDC code from Ulrich.
- ; v5.05: 960530 Final version of FDC code. Bug fix from Brad Thomas. Updated
- ; documentation.
- ; v5.06: 960??? SB code from Ulrich.
- ; v5.07: 960805 Updated documentation.
- ; v5.08: 960907 Use SB_Pause and SB_continue where appropriate. SB_Sound
- ; v1.04 added. New setup item DMAblocklen.
- ; v5.09: 960923 Added French keyboard patches from Thierry Dymon
- ; v5.10: 960929 ROM 5 and 6 can now be loaded, and ROM 7 is optional, too.
-
- Versions released by Ulrich Doewich:
-
- ; v5.20: 970421 Sorry.. didn't keep a detailed, _separate_ log of what
- changed from build to build. Please refer to the
- WHATSNEW.TXT file and the source package for the complete
- low-down.
-
