Changes in 0.9.7
-----------------

o CPU.C has got several new macros for stack (PH, PHW, PL) and memory
  access (dGetByte, dPutByte, dGetWord). This is intented for easier
  implementation of future memory management. <Jason>

o new command line switch "-nopatchall" and option in config file
  "ENABLE_ROM_PATCH". If you disable ROM patches (either by setting the
  ENABLE_ROM_PATCH to 0 or by using "-nopatchall") it will automatically
  disable the SIO patch as well. But the main purpose of this is to get
  a clean Atari800 ROM so Self-Test is happy when testing CRC and
  some games that search for certain device in HATABS do work now.
  <idea by Jindrich>

o new undocumented GTIA priority ("transparent missiles") added. The 5th
  player colour of missiles is transparent in mode 9 and 11.
  Also it fixes a bug in the earlier implementation of gtia mode 11
  There is also a major change in the way priorities are handled which
  is designed to be faster somewhat, it seems to help a bit with demos
  that cover the screen with players. It will probably not help too much
  for other programs. <Perry>

o #define BIG_ENDIAN -> POKEYSND_BIG_ENDIAN (why Linux-ix86 defines
  BIG_ENDIAN???). <Perry>

o NTSC patch to get Joust running under A5200. <Perry>

o new: support of R-Time 8 cartridge. Try to type 'date' or 'time' under 
  SpartaDOS. <Jason>

o new: artifacting in ANTIC mode 2. <Perry>

o PM DOS version: sound routines (DOSSOUND.C) do not need SEAL library
  as it uses ALLEGRO lib now. ALLEGRO is capable of sound card auto detection.
  New code uses just double buffering (previously tripple buffered) and the
  value of gain was reduced to fix some problems with digital sound.
  Edit ALLEGRO.CFG to change sample rate and thus sound quality.
  <Perry>

o CPU 6502 emulation core adapted to not use goto's all over the place.
  Also the jump table was replaced by switch() statement, which should be
  optimized into jump table by any modern compiler, anyway.
  This has various results - under MSVC it speeded up the emulation,
  while under GNU C on MC68040 it actually slowed the emulator down
  (about 10%, which is too much). The new core is available in file
  CPU_NOGOTO.C and is not used by default, however you may experiment
  with it under your architecture. <Rich>

o SIO DVSTAT byte 1 changed from 128 to 255 in order to get Strip Poker
  running. <Rich>

o WIN32 related additions and changes <Rich>

o stricmp() -> strcasecmp() in ui.c

o TVmode enum members PAL and NTSC had to be changed to TV_PAL and TV_NTSC
  (PAL and NTSC were already defined in falcon.h header file)

o ESCape code for SIO invoking (at 0xe459) has got an additional check to
  ensure that SIO emulation layer is not called by mistake when CPU gets
  some random data instead of instructions (it used to cause mysterious
  locks up of emulator). All other system patches should be protected this
  way, I think.

o ADDLOG and BACKUP_MSG were replaced with one universal routine in log.c
  called Aprint (syntax same as printf). All printf() should be replaced
  with this Aprint() routine that buffers the messages on systems where
  the emulator runs in a special graphics mode (DOS/Falcon/Win32) and does
  not want to have screen filled with a mess instead of debug reports.

o Falcon port cleaned up a lot: cflib removed, three different routines
  for chunky-to-planar conversion in 320x240, 352x240 and 384x240 resolutions
  were replaced with one universal routine that works in any resolution and
  centers the screen view automatically. The default resolution for Falcon
  is 336x240 now. It also is NOT a Falcon specific port anymore, as it now 
  supports any Atari compatible hardware with MC68020 or higher and 8-bit
  color graphics (320x240 is the minimum resolution for starting emulator).
  It also supports LED emulation (floppy LED blinking during SIO activity).

o source is compilable with -Wall, all previously uninitialised variables are
  set to 0.

o UI: long file names in Disk Selection dialog are shortened now. <Jindrich>

o Colour Artifacting! Use '-artif <MODE>' command line switch to enable
  the artifacting. Mode is number between 0 and 3. <Perry>

o the WIN32 specific code for artifacting in antic was removed.

o DOS specific files clean up and fixes (a lot). <Golda>

o PIA: fixed support for four joysticks in Atari800, tested on some games.
  Improved emulation of joystick ports on XL/XE. Some games obviously
  switch the ports into output state(!) and then read it. One would say
  there is nothing but $FF when the port is in output state and you read
  from it, but the real life is different. Atari800 emulator now supports
  this hardware trick correctly. <Golda>

o UI: better directory tree browsing support in Select Disk, in MS-DOS you
  can even select disk drives. <Golda>


Changes in 0.9.6
----------------

o DOS: keyboard and joystick handling changed a lot. Joysticks emulated
  on keyboard can now be freely defined to (nearly) any key combinations
  using comfortable JOYCFG.EXE tool. Besides, there are two modes of
  keyboard: Joystick mode and Normal mode. In Joystick mode the keypresses
  to joystick predefined keys are not passed to emulated environment.
  You can switch between Joystick and Normal mode on-the-fly by pressing
  the F7 key. <Golda>

o Falcon: NOVA graphics extended: 336x240 or 672x480 (double size)

o UI: the too fast autorepeat was fixed - by disabling the repeat altogether.

o SIO: serious bug in CopyToMem fixed. No more rewritten ROM OS. <Jindrich>

o ANTIC patch: no player DMA without missile DMA. <Perry>

o SIO: missing 'else' in DIR routines. <Perry>

o Allegro VGA: updated Makefile and fixed ShutdownVGA(). <Perry, Golda>

o VCOUNT patch <suggested by Thor, but developed and tested by Perry>

o PIA_Initialise() should initialise PORTA to 0.

o PIA registers are mirrored not only in Atari800, but in XL/XE models
  as well (thus addr&=0xff03). Bounty Bob runs now?

o DOS: VESA2 mode support (about three times faster than X-mode). VESA2
  also preserves the refresh rate. You can disable VESA2 modes by switch
  -novesa. Also colour pallete initialisation is faster now. <Golda>

o DOS: Atari_Set_LED function (use -DSET_LED to enable that). <Golda>

o UI: the last ESC keypress is not passed to the emulated program anymore.
  <Golda>

o Monitor: pressing [Return/Enter] can be used for single stepping as well.
  <Golda>

o new routine for saving of screenshot in 336x240 size as PCX. So far used
  in DOS and Falcon ports (press F10 to save current screen into a file).
  <Golda>

o the Atari keyboard should now react quickly enough. DOS port contains
  keyboard buffer for last two keys. <Golda>

o fix for initialisation of PORTA <David Firth>

o DOS port: better joystick autodetection <Michael Beck>

o several fixes for more ANSI like C code <various people>

o ANTIC: fix for DLIST counter. <Thor, Perry>

o ANTIC: several more hardware registers are unreadable. <Perry>


Changes in 0.9.5
----------------

o ANTIC: fix for scrolling of empty lines. <Perry>

o CPU: little fix in remembering last N jumps. <Golda>

o new command line option: '-basic' to override Hold_Option in cfg file

o UI: you can now go into folders when selecting image in Disk Management
  <Preston>

o DOS port - finally full resolution 320x240, 320x480 interlaced. <Golda>

o SIO: ATR images created by SIO2PC are readable now. Also Read/Write
  Config was updated to reflect real XF551. <Michael>

o monitor continues last command by pressing [Return/Enter] key. <Michael>

o PIA: reading PORTA fixed (now works exactly like real Atari800,
  not compatible with Atari5200 yet). <Perry>

o UI fix: it's possible to disable disk drive by [Space] again.

o Gtia fix: CONSOL (Start/Select/Option keys) handling. <Perry>

o Pokeysnd: poly4 and poly5 bit fields were changed for more accurate
  sound emulation. The original values are still available with
  -DPOKEY23_POLY. <Perry>


Changes in 0.9.4
----------------

o CPU fixes: several unofficial instructions compared with real
  Atari800XE and their emulation fixed. ADC/SBC "V" bit bug found
  and fixed (Thor's code used, which in turn was taken from Frodo
  emulator, AFAIK). Compatibility greatly improved again! <RASTER>

o Antic fix: cycle counting when DMA is disabled (improves sound
  quality in non-interrupt driven sound update routines). <Perry>

o Voxware sound driver updated (tested under Linux).
  pokey11.[ch] files removed. <Robert Brewer>

o the crashing in UI when switching to Atari5200 mode fixed. <Perry>

o internal monitor improved (symbolic names for often used hardware
  registers etc). Line assembler implemented. Single instruction
  step mode implemented.
  Monitor remembers not only last N PC addresses, but also
  last N jumps. To enable these features edit your Makefile
  CFLAGS = -DMONITOR_BREAK -DMONITOR_HINTS -DMONITOR_ASSEMBLER.
  <Golda>

o additional WIN32 code (Atari800 User Interface is used in
  Windows port now) <Rich>

o all Hardware_GetByte(address) routines return 0xff for unknown 
  address now.

o fixed several files so Makefile.allegro works now. <Perry>

o NMIEN is not readable now. <Thor>


Changes in 0.9.3
----------------

o POKEY interrupts implemented (inspired by Thor's version).
  Ghostbusters run now! :-)

o NOVA graphics support on Atari TT/Falcon computers finished.
  Atari800 is no longer Atari Falcon specific port, now it works
  on any TOS compatible machine with MC68020 or higher and a NOVA
  graphics card (please test in on Medusa, Hades and Milan machines)

o A special check for pending IRQ put into CLI, PLP and RTI insns.
  It's a macro for speed reasons, though a function might be more
  appropriate.

o A new function GenerateIRQ() was written in CPU module and is used
  where needed (ATARI and POKEY modules).

o Handling of IRQ's changed. Before, we tested for IRQEN (is interrupt
  enabled?) and then (in positive case) we set IRQST.
  Now, we always set the IRQST and then we take an action only if
  IRQEN is OK. I don't know if it's OK, I have just been told that
  more demos work with this.

o all HardwareGetByte(address) routines return now 0 for unknown 
  address (probably not ideal, but deterministic at least).

o several routines from ANTIC, CPU and POKEYSND modules moved to
  POKEY module, where they actually belong.

o CPU emulation fixed (INDIRECT_X mode was overflowing) <Thor,
  Golda, RASTER>

o CPU and Antic speeded up *slightly* by using type casts instead
  of direct anding with 0xff (the compiler got a chance to 
  optimize it at least). <RASTER>

o a lot of uneccessary castings to (UWORD) and (UBYTE) was removed
  from CPU emulation

o DiskDir of UI enhanced - now you can define up to eight
  directories where disk images are stored - then you can
  go through these directories in Disk Management by pressing
  TAB key. <Golda>

o fixed sorting of file list in Disk management in DOS port 
  (a speciality of strcmp() function of DJGPP libc). <Golda>


Changes in 0.9.2
----------------

o LPTjoy implemented. Now you can connect up to three old style
  CX-40 (Atari, Amiga digital joysticks) to the printer ports
  of your PC (via a very simple interface). Then you just specify
  "-LPTjoy1" on command line for joystick on LPT1 etc.
  LPTjoy idea came from Petr Sumbera.

o m68k assembler CPU emulation was updated to reflect recent
  changes in CPU module <Empty Head>.

o preliminary support for NOVA graphics on Falcon

o Allegro joystick routines slightly improved (now you can
  play even without real joystick)

o Atari800Win changes were put in the main source tree <Rich>

o after selecting another OS from UI emulator doesn't hang if
  there is no ROM file.


Changes in 0.9.1
----------------

o new POKEY v2.4 with sound channels filtering! Exclusively
  written by Ron Fries for Atari800 emulator. Thanks, Ron!

o merge of Perry's and (RASTER & Petr)'s source tree - great!
  Current source can be compiled for DOS by either Makefile.dos
  or by Perry's Makefile.allegro. Perry's Makefile needs DOS game
  library Allegro. The only functional difference between these
  two DOS versions is that Makefile.allegro enables keyclicks
  (due to different sound handling).

o major rewrite of DOS keyboard emulation - now allows two
  modes of operation: native (the labels on English PC keyboard
  are valid) and original (the keyboard layout is the same as
  the original Atari800 keyboard). You can switch between these
  two modes on-the-fly by pressing Control+F1 and Shift+F1).
  Better handling of START/SELECT/OPTION keys (these console keys
  are independent of the rest of keyboard).
  Screen view movement changed to Control-numeric pad (just
  like emulated joy, but with Control key). <RASTER>

o ANTIC speeded up by narrowing the screen width to 42 chars
  (originally it was 48 chars wide, but no TV can show more 
  than about 43 chars..). This should speed things up for
  about 10% in wide modes and PM graphics. <Perry>

o Emulation of 320 kB of memory added. Two different modes are
  supported - Rambo and Compy Shop. Extended memory tested by
  Q-meg (alternative operating system for Atari320XE).
  ROM/ShadowRAM and AtariXL Basic switching optimized. <RASTER>

o Atari5200 emulation corrected (loading of ROMs, keyboard,
  paddles). Special support for Bounty Bob on Atari5200
  added. <Perry>

o new SIO code that supports formatting (written by <thor>,
  updated by Perry and Petr).


Changes in 0.9.0
----------------

o slight speed up in antic.c <Perry>

o the right-most vertical line was missing on screen <RASTER>

o DOS: BREAK key should not have auto-repeat,  Invers key added
  <RASTER>

o ANTIC now contains #ifdef POKEY_UPDATE. That should be defined
  in Makefiles for architectures where it's impossible to update
  sound buffers in DMA interrupt (i.e. Unices etc)

o source cleaned up (no C++ style of comments), docs updated


Changes in 0.8.9
----------------

o ANTIC's DIRECT_VIDEO mode was completely rewritten. Now it is the
  default mode of emulation, much faster than the previous approach.
  This version of ANTIC is also 'line-oriented' - that means video
  emulation is accurate to single scanlines. It allows such tricks
  like changing charset during displaying an ANTIC text mode line.
  ANTIC's scrolling in both horizontal and vertical direction is now
  supported in all graphics modes. Thanks Perry for all these things.

o GTIA now supports all possible combinations of PMG collisions. It
  also supports third colour (many games are much more colourful now,
  just like they were on original Atari800). Thanks Thomas Richter and
  Perry.

o -configure now preloads the default filenames of ROM images. It also
  presets hold_option to 1 (for game players is better not to confuse
  them with Atari Basic). <RASTER>

o xcolpf1 kludge was removed (antic, gtia, rt-config files).
o DIRECT_VIDEO support was removed (configure.c)
o the compilation config file is named atari800.djgpp on DOS, so it
  finally doesn't collide with atari800.cfg (config file of emulator itself)
o sio.c opens files in binary mode - works on DOS

o Atari800 monitor changes: disassembler rewritten (now recognizes all 256
  opcodes and displays also cycles and hex codes), different (more logical?)
  commands: [D]isassembler, [C]hange memory, dump [M]emory (previously Y, M, D)
  <RASTER>

o Fixed DMACTL and GRACTL registers (difference between enabled PMG and enabled
  DMA for PMG). <RASTER>

o Introduced PMG flickering (try out POKE 53248,160:POKE 704,14:POKE 53277,3).
  <RASTER>

o DOS keyboard: added Ctrl-1 (stops scrolling), Ctrl-2 (bell), Ctrl-3 (EOF) and
  HOME key clears screen, END key stands for Atari BREAK key. INSERT and DELETE
  keys insert and delete chars or whole lines (with Shift and Control keys).


Changes in 0.8.8
----------------

o Antic, GTIA and CPU are now synchronized. Very precise timing
  (up to 99.87% compared to real Atari800XE) with CPU cycle counting
  was implemented by RASTER. This should be the final solution for
  numerous DLI problems.

Changes in 0.8.7
----------------

o snailmeter (speed indicator on the screen) is disabled automatically
  when the host computer is fast enough for emulating the Atari800 at 
  full speed.

o Atari_Scanline() function was optimized - should be up to twice as fast
  as was before.

o Falcon: keyboard emulation of joystick was fixed once more. Now you can
  hold down several keys at once and it works OK.

o DOS: joystick is autodetected. If not present, keyboard emulates joy1.
  If real joy is detected, keyboard emulates joy2. If "-joyswap" command
  on command line is used, the joy1 and joy2 are exchanged.

Changes in 0.8.6
----------------

o improved IRQ handling in CPU (CLI instruction) - now Rescue on Fractalus
  reacts on keyboard presses

o Falcon: real DMA sound with interrupt driven buffer recalculation using
  Ron Fries POKEY 2.3

o DOS: keyboard fix of HASH mark (Shift-3)

o Falcon: keyboard fix of joystick emulation

o DOS version starts even when sound card is not initialized (emulator is now
  able to run under WindowsNT 4.0)

o Falcon detects current video mode and doesn't touch VIDEL registers 
  if it's 320/352/384x240x8bp (see the -resolution switch) - Atari800 should
  now run on RGB monitors as well.

o fixed little typo in BACK_SLASH (thanks Perry)

o improved DOS and Falcon keyboard emulation (common KEYPRESSED and SHIFT_KEY)
  DOS version now recognizes extended keys properly - joystick emulation is OK
  (Chimera, BruceLee and others are now playable)

o XL operating system is turned on in Coldstart routine.

o keyboard IRQ are set only if allowed by IRQEN

o DOS port emulates TAB and HELP key (HELP is mapped to F10 - not optimal,
  should be changed to another key - perhaps F6, which is useless in XL mode)

o DOS port has faster screen update with dosmemputl (Perry)

o files on virtual drive are opened in binary mode (Perry)
  and are listed in uppercase (RASTER's suggestion)

o fixed bug in SIO_Mount causing crashes when mounting drives in Disk management

o in System menu (F1) copy font from operating system and not from shadow RAM
  (another XL related bug fix)

o added support for '\\' in file paths (see #define BACK_SLASH)

Changes in 0.8.4
----------------

o fixed bug in vertical scrolling (visible for example in Archon intro) - 
  thanks to Perry McFarlane


o DMA sound for Falcon version (using POKEY 2.2). Buffer recalculation is
  not interrupt driven yet.

o Error messages are buffered until the original text mode is restored
  (see #define BACKUP_MSG)

o Falcon version supports up to two joysticks

o Snailmeter :-) A kind of indicator for slow machines - it shows you
  how many times is the emulator slower than real Atari800. On my
  Afterburner (68040 @ 40 MHz) it's about three or four times slower
  than original :-( If your machine is fast enough, the snailmeter
  is not visible. So watch the lower bottom of screen! :-)

Changes in 0.8.3
----------------

o Radek Sterba (raster@infos.cz) did a marvelous work on discovering
  unofficial 6502 instructions. This CPU.C has implemented _all_ 256
  opcodes! He added more than 70 unofficial instructions, many of them
  were even unkown before. ESC code had to be changed from 0xff to 0xf2
  (0xff is a kind of 'regular' instruction, while 0xf2 is the CIM).
  Atari800 is the world's first 6502 emulator with full instruction set!
  100% software compatibility with original 6502.

o I've integrated his code and fixed JMP (addr) for addr crossing 
  page boundary (6502 was 'buggy', though 65C02 should had this fixed).

o IRQ variable has been changed from int to UBYTE (for C it shouldn't matter
  and it helps in the m68k asm code).

o Disk images created by XFormer and its utilities (having extension
  .XFD or .DD) may be of double density - I implemented it in sio.c
  (see #ifdef ORIGINAL_XFD_CODE). Tested and works (glad to get it working,
  because I have a lot of XFD images).

o In DOS/VGA version you can move the 320x200 screen around with Ctrl-Arrows
  to see full 384x240 resolution of original Atari800. To restore the VGA
  screen back to center press F10.

o DOS/VGA version supports one real PC joystick (emulated in port 1).
  You still can use the numeric keypad as emulated joystick - by default
  in port 1, or in port 2 with "-joyswap" command line switch. Joystick
  doesn't have the ghost-moves (interrupts are disabled during joy reading).
  Also joystick is not read whenever the Atari800 wants it, but only in the
  keyboard routine (i.e. regularly 50 times per second, basically in VBL).
  This was important to prevent a game reading joy port too often to hang
  or slow the emulation down (reading of PC joystick takes some time).

o DOS port has finally got wonderfully clear sound, thanks to Ron Fries'
  SoundBlaster Driver 1.2 and new, little/big-endian aware POKEY 2.2 routines.

o New monitor S command for searching a value in memory.

o The best news: found the reason why so many games didn't work in XL mode.
  Fixed one MMU bug (XL didn't have TRIG2 and TRIG3 was connected to
  cartridge) and introduced one MMU workaround (many 800-only games put
  zero to PORTB. That's why Tapper and other games didn't work). Now the
  compatibility ratio of Atari800 in XL/XE mode is at 97% or higher - 
  definitely the most compatible Atari800/XL/XE emulator in the world.

Changes in 0.8.2Petr
----------------

o Fixed wrong missile width (all missiles had the same width) - now River
  Raid looks much better.

o Added 28 cycles in Antic after executing DLI - it was absolutely needed,
  because otherwise the interrupt routine was executed too late and the
  effects (color or font change) occured with another Antic line - now
  Pitfall II has the score displayed in numbers and not in characters.

o Added several checks into SIO code for seeking() after end of file - 
  on Falcon it caused enlarging of disk images (for example the well
  known MENU.ATR has original size 1296 bytes, but after rebooting
  of Atari800 the file was enlarged to 2598672 bytes). Maybe it's
  a hidden endianess problem in SIO code? It happened on Amiga, too.

o Added a method of invoking Monitor - by pressing the F8 key anytime
  during emulation.

o Added BREAK command into Monitor. Now it's possible to enter monitor,
  use command BREAK <addr> and then CONT. The emulator then runs until
  the PC (program counter) is exactly <addr>. Then the monitor is invoked
  again.

o DOS version has got joystick support and also sound support using Ron
  Fries Pokey Emulation 2.0. The joystick is OK, but the sound is not
  clear - need to change to interrupt driven sound buffer generating.

o Atari800 has been ported to Atari Falcon (32-bit machine with MC68030
  or MC68040 and flexible graphics processor). Besides the port this
  Falcon version contains special CPU 6502 emulation written in pure
  MC68030 assembler by Empty Head (Karel Rous), special very fast routines
  for chunky2planar conversion (written by Douglas Little @ Black Scorpion)
  and special code for VIDEL programming (provided by Douglas as well).
  The keyboard and joystick emulation, the port itself and the fixes 
  mentioned above were done by me, Petr Stehlik (stehlik@cas3.zlin.vutbr.cz).

Changes in 0.8.2David
----------------

o New Monitor READ command to load file into memory.
o New Monitor COLDSTART command to perform a coldstart.
o New Monitor WARMSTART command to perform a warmstart.
o New Monitor F command to fill memory range with a value.
o Prevention of "config.h" being included during compilation for Amiga.
o Improved MS-DOS keyboard handling. The most noticable difference is
  that the keypad joystick emulation now returns to centre when the
  key is released.
o Re-instated replacement OS - Allows Defender and Star Raider to
  run without the Atari OS Roms.
o Added Atari Falcon Support - Thanks to Petr Stehlik.
o NAS (Network Audio System) support is now obsolete. The entries have
  been removed from the makefile and the intention is to remove the
  obsolete code before the next release.

Changes in 0.8.1
----------------

o Added -private_cmap flag for X11 version.

o Correction to handling of 6502 V flag during ADC and SBC operations.

Changes in 0.8.0
----------------

o Added Ron Fries Pokey Emulation routines for sound in Linux.
  A million thanks to Ron for releasing these routines - I've
  put off using sound for ages but it took less than an evening
  to add sound using these routines :-)

  Sound is setup for Linux using /dev/dsp but it also seems to
  produce something using /dev/audio, which leads me to believe
  that it should work on most Unix boxes with a little work.
  Patches welcomed :-)

  In order to support sound I've added a few new command line
  options:-

  -sound and -nosound do what you'd expect.

  -dsp_divisor takes a decimal value which alters the quality of
               the sound output. It is used to work out how much
               sound should be created each time the screen is
               refreshed. Ideally it should be 50 (PAL) or 60 (NTSC)
               but I've found that the best value to use is about
               5 less than the emulators screen refresh rate WITH
               SOUND DISABLED. If the values is to high you will
               get gaps in the sound. If the value is to low the
               emulator will run slower than it should.

               I strongly suggest you experiment with this parameter
               in order to get both the best sound and performance.

o Support for an Experimental New Cartridge Format - with the use of
  OSS Super Cartridges there is no way of automatically
  distinguishing standard 16K cartridges from the various Super
  Cartridges. Hopefully this format will do for cartridges what ATR
  files did for disk images. Feedback and view would be welcomed
  especially from the other Emulator Authors.

  The current format is :-

  first 4 bytes containing 'C' 'A' 'R' 'T'.
  next 4 bytes containing cartridge type in MSB format.

    Type 1 - Standard 8K Cartridge
    Type 2 - Standard 16K Cartridge
    Type 3 - OSS Super Cartridge (I heard rumours that there are two
             different types of OSS Cartridges)
    Type 4 - Atari 5200 Cartridge

    Note: There is probably a case for extra cartridge types
          indicating the system that needs to be emulated.
          e.g. Standard 8K Cartridge (800 Mode Only).

  next 4 bytes containing cartridge checksum in MSB format (ROM only).
  next 4 bytes are currently unused.
  followed immediately with the ROM data, typically 8, 16 or 32K.

  In the next version I'm intending on adding:-
    32 bytes for Cartridge Name
    32 bytes for Cartridge Serial Number
    32 bytes for Manufacturer

  The current version of the emulator includes options in the
  Cartridge Management screen to Create Cartridges in the above
  format but be warned this format is likely to change.

Changes in 0.7.1
----------------

o Note: I now consider the new Menu System that runs in the Emulated
        Atari's window to be the prefered User Interface. I have no
        intention of doing any further development for XVIEW

o Cartridge Management added to Menu.

o Removed FFP Code.

Changes in 0.7.0
----------------

o F1 enters Menu System at any time. ESC returns you to the previous
  screen. Items are lcoated using the cursor keys and selected by
  either RETURN, SPACE, TAB or BACKSPACE. In most cases these keys
  can be used interchangeably, the exception is in the Disk Management
  Screen where RETURN is used to select a new disk and SPACE, TAB and
  BACKSPACE are used to eject a disk - If there is no disk in the
  virtual drive then SPACE, TAB and BACKSPACE will switch the drive
  off (Useful for Shamus).

o X11, SVGALIB & DOS - F5 is now Warmstart and Shift F5 is Coldstart.

o X11 - F8 Single Shot Screen Dump, Shift F8 continuous Screen Dumps.

o MS-DOS version runs about three times quicker now that the emulator is
  synchronising with a high resolution timer.

o MS-DOS version resets the screen back to text mode when finished.

Changes in 0.6.2
----------------

o Antic Modes 2, 3 and f now display the normal Atari Colour and
  Luminance by default. Extended Antic Modes 2, 3 and f are enabled
  by starting the emulator with the "-xcolpf1" command line option.
  This allows two completely different colours to be displayed in
  these modes - as previously.

o Improved Run-Time Configuration. Starting emulator with the "-configure"
  command line option allows configuration of several items:-

     1. Location of OS Roms
     2. Default Directory for Disk Images
     3. Default Directory for ROM Images
     4. Default Directory for H1, H2, H3 and H4 pseudo devices
     5. Command Print File (for Printer Support)
     6. Default Screen Refresh Ratio
     7. Default Startup System (OS/A, OS/B, XL, XE, 5200)
     8. Default TV Mode (PAL, NTSC)
     9. Hold Option during Coldstart
    10. Enable C000-CFFF RAM in Atari 800 mode
    11. Enable SIO Patch
    12. Enable FFP Patch
    13. Enable Extended COLPF1 (Two true colours in Antic Modes 2, 3 & F)

  The emulator writes a file called "atari800.cfg" in your default
  directory. When reading the configuration the emulator first checks
  to see if you've specified a configuration on the command line with
  the "-config" option otherwise it first tries to read a configuration
  file from your default directory, failing this it then tries to read
  a configuration file from "/etc/atari800.cfg".

o JoyMouse for Toshiba Portables running SVGALIB - Probably also
  suitable for Trackball devices with minor modifications.

Changes in 0.6.1
----------------

*** IMPORTANT MESSAGE for EXISTING Users of Atari800 (Source Versions)

You will need to make some changes during the sytem configuration
stage - the emulator now expects the full path to each of the system
ROM images to be explicitly stated. If you don't have all the ROM
images then just pretend you have!

o FPS and SIO Monitor are no longer compile time configuration options.
  Enabled by "-fps" or "-sio" command line option or via an XVIEW
  pulldown menu.
o Motif fileselector retains state from one invocation to the next.
o Configuration program detects if longwords need to be aligned.
o Modification to X11 Paddle Emulation.
o Removed hardcoded paths in MOTIF code.
o Various fixes for curses mode.
o Correction to Colours in Antic Modes 4&5 causing Incorrect colours
  in Rally Speedway, Galactic Chase and Mr. DO)
o Disabled DiskChange KEY (F8) in X11 version.
o Added "-nobasic" command line parameter.
o Added "-osa_rom", "-osb_rom", "-xlxe_rom", "-5200_rom" and "-basic_rom".
  These command line options are used to specify the location of
  various system ROMs on mis-configured systems or binary distributions.

Note: To prevent cluttering up the CHANGES file all credits are listed
      in the CREDITS file.

Changes in 0.6.0
----------------

- Emulator can now be compiled for DOS using the DJGPP port of GCC (Thanks
  to Ivo van Poorten)

Thanks to Maximum Entropy for the following Changes:-
- Implementation of Disable Drive menu item for Motif.
- Fixed scrolling problem for machines that can't access longwords on word
  boundaries (e.g. SGI and SPARC).
- Added FPS Monitor to X11 and Motif versions.
- Changes to pattern matching for H: device.

Changes in 0.5.5
----------------

Thanks to Maximum Entropy for the following Changes:-
- Various corrections to MOTIF code.
- MOTIF callbacks for Insert Disk, Eject Disk and Insert ROM
- Bug Fixes in sio.c
- Bug Fix to devices.c allowing DOS 2.5 to get a directory of H:
- Bug Fix to monitor.c (EOF on INPUT + Blank Lines)
- Undocumented commands added to monitors HELP command.

Changes in 0.5.4
----------------

- Made Emulator C++ Friendly.
- BASIC version has not been working since CPU cycles were allocated during
  scanlines processing. This problem was caused because the BASIC version
  doesn't generate any scanlines and therefore didn't execute any
  instructions. This version fixes the problem.

Changes in 0.5.3
----------------

- Removed GetWord macro from cpu.c
- Added XVIEW option to disable drive (via SIO_DisableDrive()). This
  allows SHAMUS to work. The drive is automatically re-enabled next
  time a disk is inserted.

Changes in 0.5.2
----------------

- Made CPU timing more accurate: It now issue 114 clock cycles per scanline
  instead of 48 instructions.
- Removed obsolete functions: GetBinaryWord() and BinaryLoad().
- Handle PORTA Direction Control Register. Fixes Joystick problem in Caverns
  of Mars 1.
- The atari_basic array was incorrectly defined in pia.c as [8129]. This
  has now been corrected to [8192] (Thanks to Chris Palmer).

Changes in 0.5.1
----------------

- Changed handling of CONSOL for X11 versions - previously it was hard
  to start some games.
- Changed address of 5200 POKEY chip. The information I have states that
  it is located in page $eb, but evidence in a disassembled cart suggests
  its at $e8. Of course it could appear in both pages, does anyone
  know for sure?
- CPU time allocation is now performed entirely within "antic.c". This is
  a pre-condition for switchable PAL/NTCS modes.
- Compile time configurable to either PAL [default] or NTCS system.
- "-countdown" option has been removed.

Changes in 0.5.0
----------------

- Simplified interface to CPU module.
- DIRECT_VIDEO now works with PMG collision detection. This option increases
  performance by about 28% but can result in different colours being displayed.
  This is because this option relies on COLPF0, COLPF1, COLPF2, COLPF3 and
  COLBK all having different values, hence the emulator sometimes modifies
  the colours :-( This option can be enabled during the configuration phase.
- Correction to ANTIC Mode 5 Vertical Scrolling.
- Correction to PMG DMA Code - Demon Attack now works OK.
- Added code to limit the emulator to 50fps - this will not have any
  effect if your machine can't run the emulator greater than 50fps.
  F10 in X11, XVIEW, MOTIF and SVGALIB versions toggles the limit on/off.
  When the limit is off the emulator will go as fast as it can.
- Path to directory containing the OS ROM images is now defined during
  the configuration phase (Declaration of ATARI_LIBRARY has been removed
  from the Makefile).
- Correction to handling of PMG DMA - Pitfall II now Works.
- The unused bits in PMBASE are now ignored correcting errors in Atari Chess
  and Frogger.

Changes in 0.4.5
----------------

- Added a compile time configuration option to control the default
  screen refresh rate. In previous version of the emulator the default
  rate has been 4 frame: draw 1 skip 3. From this version you will
  be prompted for the default during the compile stage (except VMS and
  AMIGA which still default to 4). A value of 1 is required for the
  most accurate emulation. Values other than one can produce some
  collision detection problems on a few programs (e.g. Burried Bucks).
- Split Custom Chip code into seperate files.
- Added 5200 Emulation Code - Runs program but needs modifications to
  support 5200 controllers. The 2K OS ROM must be called "atari5200.rom"
  and placed in the same directory as the other OS ROMS.
- Linux Joystick enabled by configuration program. There are nolonger
  any makefile targets containing "joystick".
- Removed code relating to Emulated Operating System.
- Added option that displays the number of Frames per Second. This option
  is enabled within the configuration program and currently only works
  with the XVIEW version.

Changes in 0.4.4
----------------

- SpartaDOS 3.2 works for both Read and Write Access.
- Alternate Reality "The City" now works.
- Added interrupt timings for Invalid SIO commands.
- Support for Direct Serial I/O Write and Put sectors commands.
- Correction for Double Density ATR files.

Changes in 0.4.3
----------------

- Corrected a Bug that prevented DOS 2.5 from copying files to/from H:
- Re-instated F8 Disk Change function for non XVIEW/MOTIF/AMIGA Systems.

Changes in 0.4.2
----------------

- Test code for faster screen generation, enabled by defining DIRECT_VIDEO
  within "atari_custom.c". It needs a little more thought with respect to
  collision detection, hence it is disabled by default.
- Better PMG Priority Handling.
- Tidied up code accessing hardware registers
- Changed handling of B, D and I flags.
- Changed handling of NMIs.

Changes in 0.4.1
----------------

- Flashes background colour while performing direct Serial I/O
- Minor optimisation to Player/Player collision detection
- Minor changes in CPU emulation
- Correction to new cartridge code causing it to fail under XL/XE
  emulation (Thanks to Neil Shipp)
- New targets in the Makefile for freebsd systems (Thanks to Ivo
  van Poorten)

Changes in 0.4.0
----------------

- Added MOTIF User Interface
- Support for DEC-Windows under VMS (Thanks to Chris F Chiesa)
- Removed dependency on 'ncycles' global variable.
- Support for direct access to serial port hardware - The emulator will
  now run Alternate Reality "The Dungeon" (I haven't tried the others)
- Modified handling of XL/XE memory.
- Fixed the GTIA modes which broke after X Window shared memory support
  was added in version 0.3.0
- Correction allowing Montezumas Revenge to work again.

Changes in 0.3.3
----------------

- New System menu in XVIEW version allowing selection of operating
  system etc.
- Amiga: Iconify working.
- Amiga: System menu contains options for Insert ROM, Remove ROM,
  Enable PILL, Selection of Operating System and all previous disk
  options.
- Amiga: Help menu option is now working using Multiview.

Changes in 0.3.2
----------------

- Modified BRK instruction to take account of the I flag. The BRK
  instruction is ignored if the I flag is set.
- Added all unofficial NOP opcodes.
- New cartridge handling. The XVIEW version provides menu items
  enabling the insertion and removal of cartridges.

Changes in 0.3.1
----------------

- Defined PRINT_COMMAND in devices.c for Amiga
- Minor optimisation to PMG handling
- Modified DLI Handling and ScanLine processing

Changes in 0.3.0
----------------

- Support for Atari 130XE memory banks (Antic currently accesses the
  same bank as the CPU)
- XVIEW Exit item on the Disk menu.
- Printer device calls tmpnam() to allocate a temporary filename for
  the spool file.
- XView version didn't enable HELP key for XL and XE emulation.
- X11 Backspace keys works in the same ways as the Delete key.
  (Thanks to Cyrus Malek)
- Reset and Coldstart now work during XL and XE emulation.
- Added OK button to XVIEW controller and performance dialog boxes.
- Optional support for X11 Shared Memory Images resulting in a 32%
  speed improvement. This option can only be used in conjunction
  with the small screen display. Type make by itself to obtain
  the new list of targets. "-shm" target extension enables this
  option.
- Simple configuration program to avoid editing the Makefile as ofter.
  make will invoke it the first time and afterwards "make config" can
  be used. It currently handles the directories for the H: device, the
  disk image directory for the XVIEW file chooser and the command used
  to send a file to the printer. The print command should contain a %s
  character sequence where a filename is expected (only the first %s
  is relevant).

Changes in 0.2.7
----------------

- Renamed atari_h_device.c to a more general devices.c
- Emulator (private) opcode ESCRTS ($d2) added to support patching of OS.
- Printer device supported via Unix lpr command.
- Moved from RCS to CVS and added rcs Id keyword to all C files.
- Emulated OS: Better handling of Keyboard and ATASCII to screen
  code conversion. Editor uses LMARGN, RMARGN, ROWCRS and COLCRS.
- Many other changes to EmuOS including implementation of SETVBV
  COLDSV and WARMSV.
- Detection of X11 server supporting the MIT Shared Memory Extension in
  preperation for shared memory pixmaps.
- Corrected bug in H: device (filename extraction routine).

Changes in 0.2.6
----------------

- Corrected calculation of number of sectors and reading of double
  density ATR files (Thanks to Preston Crow)
- Correction for Linux ELF systems.
- XVIEW and NAS work under Linux/ELF
- Default directory for XVIEW Disk File Chooser is set within the
  Makefile. By default it is pointing to /usr/local/lib/atari/DISKS
- Corrected bug in Missile 0 to Playfield collision detection.
- Corrected WSYNC bug (multiple stores to WSYNC during one scanline).
  River Raid now runs correctly.
- -emuos to enable emulated operating system. Users without the
  necessary atari OS ROMs can use this option to boot disk images/ROMs.
  Currently this is very experimental and runs very little without
  problems. Defender runs perfectly but if you haven't got the OS it's
  unlikely you'll be able to get this either!
- H0: device accesses the current directory on your Unix Machine.
- H1: through H4: can access four directories specified either within
  the Makefile or via the -H1, -H2, -H3 and -H4 command line options.
  By default they are set to /usr/local/lib/atari/Hx where x is 1, 2,
  3 or 4.
- H5: through H9: duplicate H0 through H4 but have automatic ATASCII
  to ASCII translation. They are not suitable for binary files.
- All files accessed via the H: device have Unix filenames consisting
  entirely of lowercase letters.

Changes in 0.2.5
----------------

- Network Audio System support on Unix Systems [incl. Linux]. Waveform
  can be selected via the -sinewave or -squarewave options. At the
  moment it doesn't support the Atari Distortion values and switches
  channels using distortion off. This is available in XVIEW, X Window
  and Linux SVGALIB versions. The Network Audio System is freely
  available on the Internet - I used nas-1.2p2.tar.gz. Any Linux XVIEW
  version do not work when built with the Network Audio System.
  *** See BUGS file for more information ***
- Support for /dev/sequencer removed since it didn't look like it
  would ever produce satisfactory results.
- Introduced -help option that lists all options available in the
  emulator.
- Added LAX unofficial opcodes
- Corrected Vertical Fine scrolling in Antic Mode 7.
- Enhanced DLIST command in "monitor.c" which now displays the display
  list using mnemonics.
- Updated VMS command file.

Changes in 0.2.4
----------------

- Corrected mask in Atari800_GetByte() and Atari800_PutByte()
- In Atari800_PutByte(), only switch on cartridge type when an
  access is made to page $d5
- Screen generation using word access where possible.
- merged main.c with atari.c
- Fixed SVGALIB Escape and cursor keys.
- Emulated Floating Point Library which performs floating point
  arithmetic directly on your host computer - bypasses 6502 CPU
  emulation. Enabled by the -ffp option.

Changes in 0.2.3
----------------

- ADC and SBC functions are nolonger implemented as functions.
- 6502 PC, S, A, X, and Y register now handled using local
  variables. Copied to global variables on exit from cpu and
  restored on re-entry.
- Took advantage of a GCC feature: goto array[opcode]. Other compilers
  still use a switch statement.
- Amiga: DisplayScreen() tidied up
- Added DLIST command to monitor. This command shows the address of
  the display list (from hardware registers).
- Major recode of all Antic Graphics Modes. Now allows Horizontal and
  Vertial fine scrolling.
- Added an -interlace option to the SVGALIB version, giving a
  performance increase of about 10%. You would use this option to
  increase the speed of programs that must be run with a screen
  refresh rate of 1 (e.g. Burried Bucks)
- In the SVGALIB version, the F11 and F12 keys can be used to modify
  the vertical positioning of the emulated screen. F11 moves the screen
  down while F12 moves the screen up.
- Corrected a BUG causing River Raid to have corrupt screen display.

Changes in 0.2.2
----------------

- Made GetByte, GetWord and PutByte macros local to cpu.c
- Added some 386 inline asm() for some 6502 addressing modes
- Simplified Keyboard Handling
- Assembly routines for Amiga AGA screen handling

Changes in 0.2.1
----------------

- Created a new Makefile for Unix. The Amiga support is now in
  Makefile.amiga
- Sorry, but I renamed the ATARI800 environment variable to ATARI_LIBRARY
  which points to /usr/local/lib/atari by default.
- Control + Shift + Key combination for Linux SVGALIB implementation.
- SVGALIB version can be restarted after entering the monitor.
- HELP Key available in XL/XE mode
- Optional XVIEW (V3) Interface for X Window version. Allows disk changes
  using a file selector, controller configuration and access to performance
  variables.
- BREAK Key fixed
- PC Joysticks can be used with Linux (svgalib, x11 and xview) through the
  /dev/js0 and /dev/js1 devices. Second button activates the space bar
  which is very useful in Defender :-) Build with "make <system>" where
  <system> is one of:- linux-x11-joystick, linux-xview-joystick or
  linux-svgalib-joystick
- X11 Joystick emulation using keyboard re-implemented. Straight X11 can
  use either numeric keypad or cursor keys + space. XVIEW can only use
  cursor keys + space (Problem using keypad in xview!)
- Disk selector for Amiga version + controller configuration menu
- Started code to emulate SERIN and SEROUT registers. At the moment this
  is ongoing and does not work. New startup option -nopatch disables the
  SIO patch leaving the normal SIO routine in place.

Changes in 0.2.0
----------------

- Separated Playfield Scanlines from Player Missile Scanlines
- Corrected playfield colour errors in Antic modes 8 & 10
- Horizontal Fine Scrolling
- Playfield and Player/Missile Priorities
- Allow Emulator to run either as an Amiga Screen or Window
- Added Paddle support for Amiga

Changes in 0.1.9
----------------

- Corrected bug in IRQST and IRQEN
- Corrected minor bug in player missile collision detection
- Amiga version is now full screen + Menus
- Faster disk I/O
- Added ATARI800 environment variable. This allows the emulator to be
  run from different directories. If ATARI800 is unset it will still
  try to load the OS images from object/ below the current working
  directory.
- colours.h replaces colours.dat
- Added man page.
- New way of handling Joysticks, Triggers, Paddles and Console Keys
- Corrected handling of CHBASE which was causing K-RAZY ANTIKS to
  display garbage.
- Corrected handling of VCOUNT which was causing screen handling
  errors in Star Raiders (galactic map) and Henri (game screen).
- Added Sound API. A test sound implementation is available for
  the Linux SVGALIB version via /dev/sequencer - It's not very good
  and has only been used to test the API. It is enabled by starting
  the program with the -sound option. Listen to the title screens
  of Necromancer, K-Razy Antiks and Henri (these are the best
  I've heard).
- argc and argv are passed to the platform specific initialisation
  code - Atari_Initialise(). This allows platform specific options
  like -sound on the Linux SVGALIB version.
- Extra Amiga options -ocs -ecs and -aga. Currently the default is
  AGA. The -ocs and -ecs have been tested on an A1200 with the
  OCS and ECS emulation modes enabled. At the moment it is not
  guaranteed to work on real OCS or ECS equiped machines since it
  has only been tested under Workbench 3.0. Hopefully someone will
  provide some feedback.
- Another two Amiga options -grey and -colour. The -grey option
  produces a grey scale display on OCS, ECS and AGA machines. The
  -colour option produces a full colour display on AGA machines and
  up to 32 simultaneous colours on OCS and ECS machines.
- The DOUBLE_SIZE compilation flag for the X11 version has been
  replaced by a runtime options. The runtime options are -small,
  -large and -huge.

Changes in 0.1.8
----------------

- Allows direct use of GRAFP0, GRAFP1, GRAFP2, GRAFP3 and GRAFM without
  using DMA.
- -rom16 option to load standard 16K ROMs.
- -a option to load object/atariosa.rom
- -b [default] option to load object/atariosb.rom
- Simplified screen generation for host - Player missile graphics
  collision detection has been moved into 'atari_custom.c'
- Corrected read from PORTB (XL/XE emulation)
- GTIA support for *all* antic modes.
  i.e. GTIA can be enabled in graphics mode 0 (antic mode 2) just like
       a real 800. POKE 623 with 64, 128 or 192 to test.
- Amiga version can be compiled using either DICE C or GNU C - see Makefile

Changes in 0.1.7
----------------

- Issue cpu cycles during screen update (corrects VCOUNT problem)
    As a result DLI are not occuring on the correct mode line.
- Support for 256 bytes/sector ATR files
- Handle Insert, Delete and Tab keys properly
- Handle Shift + Control + A-Z properly (X11 only)
- Cartridge support tidied up (Thanks to Dave Bennett)

Changes in 0.1.6
----------------

- Correct Colours (Thanks to Chris Lam)
- Fetch correct number of screen bytes with horizontal scrolling enabled
- Speed improvements for Antic Display Modes
- Support for ATR files (128 bytes sectors only)
- Support for XL/XE ROM (Reset etc. do not work???)
- Corrected Bug in BCD SBC instruction.
- Added X11 window Expose event (Thanks to Ivo van Poorten)
- Control characters within CURSES (Thanks to Ivo van Poorten)
- Improved Portability
- Remove '-b' flag (Use -rom object/ataribas.rom instead)
- Graphical Support for Amiga 1200
- Faster 6502 Emulation
- X11 Joystick emulation now uses the mouse

Changes in 0.1.5
----------------

- CURSES text only mode (Support for various terminals)
- Display list jump instruction corrected.
- Fixed SIO module (It didn't update DSTATS)

Changes in 0.1.4
----------------

- Changed GetByte and PutByte to macros
- Added SVGALIB support for Linux which is much quicker than X11.
- Added support for OSS Super Cartridges (Thanks to Dave Bennett)
- -rom option to specify alternative cartridges
- -oss option to specify alternative OSS Super Cartridges

Changes in 0.1.3
----------------

- Compilation option for double size screen
- Trigger now initialises to not pressed
- Joystick now initialises to central
- Fifth Player support added
- Support for Paddle 0
- Preparation for changing GetByte and PutByte to macros.

Changes in 0.1.2
----------------

- Now include <stdlib.h>  in atari_custom.h

- Resets count to countdown as soon as it reaches zero. This was causing
  problems with the RESET Key - count went negative.

- Removed XImage structure. I am now updating only the pixels that have
  changed within a Pixmap. XCopyArea is used to move the Pixmap onto
  the Window. XCopyArea is not called if no pixels are changed. As a
  result I am trying a higher refresh rate.

- Correction for BASIC version - I left some X11 stuff in resulting in
  unresolved sybols.

- Remove unused status variable from atari_h_device.c

- Added some test Amiga Intuition Code - not usable (No Colour or Keyboard)
  It manages to get the 'READY' prompt up! Atari Basic Blue is one colour
  and everything else is the other. When keyboard support is added you
  will be able to use Atari Basic.

- Registers are now allocated variables within atari_custom.c. They are
  nolonger stored in main memory area.

Changes in 0.1.1 
----------------

- Outputs an error message when ROM images are not available.

Version 0.1.0
-------------

- Initial Release
