Changes since Xbeeb v0.2
========================

o Mon Nov 27 23:46:54 GMT 1995

  Added code for properly handling BDC ADC flags, as per Jouko Valta's
  65xx instruction set document


o Mon Nov 27 23:58:55 GMT 1995

  Corrected handling of address wrap-around for (ind,Y) instructions.


o Tue Nov 28 00:12:10 GMT 1995

  Corrected handling of address wrap-around for all zp,X and zp,Y
  instructions.  This removes the need for the RANGE_CHECK define.  Removed
  that, too.


o Thu Nov 30 22:48:08 GMT 1995

  Split src/opcodes.h into src/6502ops.h for NMOS 6502 op-codes and
  src/EFSops.h for dummy op-codes for emulated filing system.


o Thu Nov 30 22:50:02 GMT 1995

  Fixed a bug in src/6502.c in the OSFSC handling code so that when the PC
  is set to a new value as a result of the OSFSC call, the old value of
  the PC is not unstacked.


o Thu Nov 30 22:52:46 GMT 1995

  Added #define to src/Config.h to prevent multiple inclusion.


o Thu Nov 30 23:05:31 GMT 1995

  Added the NMOS6502 #define to src/Config.h as the default CPU type.


o Thu Nov 30 23:06:25 GMT 1995

  Added all the undocumented NMOS 6502 HALT instructions.


o Thu Nov 30 23:45:36 GMT 1995

  Added all the undocumented NMOS 6502 NOP instructions.


o Fri Dec  1 22:05:49 GMT 1995

  Changed the code for the undocumented NMOS 6520 NOP operations so that
  they load a value from memory according to their addressing mode (but
  neither store it anywhere nor set any SR flags).


o Fri Dec  1 22:13:36 GMT 1995

  Updated all disassembly instructions to give the full number of hex
  digits when displaying their parameters.


o Fri Dec  1 23:21:14 GMT 1995

  Implemented the undocumented NMOS 6502 SAX instructions
  ( Store ( A AND X )).


o Fri Dec  1 23:32:18 GMT 1995

  Implemented the undocumented NMOS 6502 ASR instruction
  ( A = LSR ( A AND #imm )).


o Sat Dec  2 00:33:21 GMT 1995

  Implemented the undocumented NMOS 6502 SLO instruction
  ( v = A << 1; M = M OR v ).
  Don't know how this operation sets the SR flags, though.

  Zalaga works for the first time!


o Sat Dec  2 13:12:51 GMT 1995

  Enabled toggling of PB7 in system VIA depending on ACR bit 6 and the
  one-shot/free-run mode of T1


o Sat Dec  2 13:44:20 GMT 1995

  Implemented User VIA T1 free-running mode.  Set the initial value of
  the User VIA ORA to 0x80.

  Planetoid/Defender now works for the first time!


o Sat Dec  2 14:24:58 GMT 1995

  Corrected value returned by read from VIA T2CL and T2CH.

  Frak! now works.


o Mon Dec  4 21:17:48 GMT 1995

  Fixed a bug in the bitmapped screen wrap-around that prevented proper
  scrolling of the screen.

  Rocket Raid, Defender and Planetoid now scroll sideways properly.


o Mon Dec  4 22:06:13 GMT 1995

  Corrected bugs in the code for reading from the CRTC, properly
  implemented the address wrap-around on the register locations and
  return values.


o Mon Dec  4 22:13:03 GMT 1995

  Corrected the address wrap-around on the ACIA register locations


o Mon Dec  4 22:30:05 GMT 1995

  Partially implemented reading the Serial ULA (with the appropriated
  address wrap-around).


o Mon Dec  4 22:47:32 GMT 1995

  Implemented address wrap-around the Video ULA and partially handled
  reading from the Video ULA register.


o Mon Dec  4 23:13:12 GMT 1995

  Set up dummy return for reads from the system VIA IRA and SR.  Implemented
  address wrap-around for memory-mapped registers in the VIA.


o Mon Dec  4 23:22:53 GMT 1995

  Set up dummy return for reads from the user VIA SR.  Implemented
  address wrap-around for memory-mapped registers in the VIA.


o Mon Dec  4 23:40:05 GMT 1995

  Set up dummy accesses to FDC and handled address wrap-around for FDC
  addresses.


o Mon Dec  4 23:57:46 GMT 1995

  Set up dummy accesses to Econet controller and handled address
  wrap-around for those addresses.

  Repton 1 now works, but gives loads of warnings for accessing
  unimplemented hardware...


o Thu Dec  7 23:48:22 GMT 1995

  Implemented the undocumented NMOS 6502 LAX instructions.


o Mon Dec 11 22:48:49 GMT 1995

  Implemented the undocumented NMOS 6502 ISB instructions.

  Penguin now works.


o Thu Dec 14 23:14:48 GMT 1995

  Implemented the undocumented NMOS 6502 ANC instructions.

  Repton 2 now runs (although the screen is corrupted).


o Thu Dec 21 18:17:12 GMT 1995

  Some tidying up of the currently implemented undocumented NMOS 6502
  instructions.


o Thu Dec 21 19:18:59 GMT 1995

  Implemented the undocumented NMOS 6502 RLA instructions
  ( ROL M; A = A AND M ).


o Fri Dec 22 20:52:08 GMT 1995

  Implemented the undocumented NMOS 6502 RRA instructions
  ( ROR M; ( A + M ) => SR, no change in A ).


o Fri Dec 22 21:26:18 GMT 1995

  Implemented the undocumented NMOS 6502 DCP instructions
  ( M--; CMP M ).

  This had repercussions in that the op-codes are used for the EFS
  code, so all that has been updated and pch/pch.c has been changed
  to reflect this.  The new trap values for the EFS code are opcodes
  which would normally hang the processor.


o Fri Dec 22 22:29:33 GMT 1995

  Implemented the undocumented NMOS 6502 SHA/SHX/SHY/SHS instructions.


o Fri Dec 22 22:56:02 GMT 1995

  Implemented the undocumented NMOS 6502 LAX/LAS instructions
  ( A = X = A & M and A = X = SP = A & M).


o Fri Dec 22 23:18:10 GMT 1995

  Implemented the undocumented NMOS6502 SBX and SBC (0xeb) instructions.


o Wed Dec 27 14:34:31 GMT 1995

  Fixed FASTCLOCK defines so that the code compiles when FASTCLOCK is not
  defined.  Also changed use of FASTCLOCK to specify how many clock ticks
  is the minimum before updating the clocks.


o Thu Dec 28 14:51:44 GMT 1995

  Commented out XK_KP_Home and XK_KP_End in src/Screen.c for those systems
  that don't have them.


o Thu Dec 28 14:54:19 GMT 1995

  Tidied up EMUL_FS defines for code which relies on the disk emulation.


o Thu Dec 28 15:27:42 GMT 1995

  Added VoxWare sound code from James Murray <jsm@jsm-net.demon.co.uk>
  and documented #define to enable it.


o Thu Dec 28 15:37:45 GMT 1995

  Changed LITTLE_ENDIAN #define to ENDIAN_6502 because of clashes with
  Linux system #defines.


o Thu Dec 28 21:42:57 GMT 1995

  Cleaned up all instruction timing code.


o Fri Dec 29 00:51:39 GMT 1995

  Added 65c12 opcodes and #define to enable emulation for that processor,
  in the process creating 65c12ops.h and EFSops.h.


o Wed Jan  3 19:34:27 GMT 1996

  Updated 6522 VIA emulation to have correct initial values for VIA
  registers wherever possible.


o Wed Jan  3 23:35:06 GMT 1996

  Separated out code for performing a reset on each piece of emulated
  hardware.


o Thu Jan  4 01:16:26 GMT 1996

  Heavily modified 6522 VIA code to separate out the input/output
  registers and what is actually on the data pins.  This has the benefits
  of tidying up the whole VIA i/o emulation and not requiring any nasty
  configuration hacks to get software to work (apart from those that exist
  because of uncompleted emulation).


o Thu Jan  4 14:27:55 GMT 1996

  Correctly coded (zp,X) addressing mode where zp+X(+1) overlaps the
  page boundary.


o Thu Jan  4 14:51:00 GMT 1996

  Added the 65c02 RMB and SMB opcodes, creating 65c02ops.h in the process.


o Thu Jan  4 16:05:29 GMT 1996

  Added support for the BBC Micro Model A using the -a command line
  switch.  Support can be removed by #define MODEL_B_ONLY in Config.h
  which will also make the emulator quicker.


o Thu Jan  4 16:44:32 GMT 1996

  Prevented multiple inclusion of any of the .h files.


o Thu Jan  4 16:55:43 GMT 1996

  Split the command-line options processing code into a separate
  module (Options.c, Options.h).


o Thu Jan  4 17:07:22 GMT 1996

  Updated the help message.


o Thu Jan  4 17:30:21 GMT 1996

  Added a command line option to set the values of the keyboard DIP
  switches.


o Thu Jan  4 22:16:13 GMT 1996

  Parenthesised all parameters of #define's in Ops.h, "just in case" :-)


o Mon Jan 8 19:55:06 GMT 1996

  Implemented bitmapped screen image as shared XImage.


o Mon Jan 15 23:50:07 GMT 1996

  Completely changed the way that the key mapping is done to make all
  games more playable by returning keys on a "position on the keyboard"
  basis rather than a character basis.


o Tue Jan 16 18:47:14 GMT 1996

  Tidied up 6522Via interrupt handling code.


o Mon Jan 22 23:14:19 GMT 1996

  Added a new window to the main Beeb screen to display the status LEDs
  and any other useful stuff.  (InfoWindow.[ch]).


o Mon Feb 12 23:34:29 GMT 1996

  Fixed RomSelect.c so that paged RAM works properly.


o Sat Feb 17 11:14:33 GMT 1996

  Integrated all the XDFS v0.7 code.


o Mon Feb 19 21:56:48 GMT 1996

  Added code to Screen.c to display the program name and version on the
  icon and title bar.


o Mon Feb 19 22:41:21 GMT 1996

  Minor corrections to allow all the source to compile without warnings
  using gcc -Wall with GCC v2.6.3.


o Fri Feb 23 00:26:16 GMT 1996

  Changed opcode #defines to circumvent a multiple #define problem on
  Solaris 2.5


o Sat Feb 24 18:27:34 GMT 1996

  Added the SHIFTLOCK_SOUND_HACK code to stop the Shift Lock light
  flickering when the sound buffer is full.  That slows down the
  emulator dramatically because of all the redrawing of the LED image.


o Sun Feb 25 18:04:23 GMT 1996

  Recoded KeymapStrict.c to use keysyms rather than keycodes so that
  the code is portable to implementations of X11 other than those on the
  PC.


o Sun Feb 25 18:15:50 GMT 1996

  Tidied up the Voxware.c source code.


o Mon Feb 26 22:43:21 GMT 1996

  More minor corrections to allow all the source to compile without
  warnings under gcc -Wall with GCC 2.7.2.


o Tue Feb 27 00:34:12 GMT 1996

  Updated with the newest XDFS code.


o Tue Feb 27 01:20:04 GMT 1996

  Major changes to the colour-handling/screen-updating code which makes
  it faster and closer to being correct.


o Wed Feb 28 01:19:16 GMT 1996

  Update the handling of BitsPerColourInfo to make it more reliable and
  accurate.


o Wed Feb 28 21:51:44 GMT 1996

  Fixed a bug that I introduced into EFS.c whilst integrating XDFS which
  cause saving files to fail.


o Thu Feb 29 00:35:59 GMT 1996

  Corrected multiple howler in EFS.c that allowed reading past the end of
  the memory array.


o Thu Feb 29 00:39:38 GMT 1996

  And another howler in the same file that allowed writing past the end
  of the target filename array in the Copy* functions.



Xbeeb v0.3 released  29th February 1996.
