Version 0.5 (first version, not complete)
-----------------------------------------
1996/08/21
- Code to simulate CPU, registers, and some small amount of memory
- Execution stops at invalid instructions
- Count clock cycles (except for page-boundary violation hits)
- Separated (and made special cases of) accesses to hardware-ports
  (Stop execution at invalid/unknown hardware accesses)
- Added just enough user-interface stuff to verify general operation

Version 0.6
-----------
1996/10/15
- Added Joystick logic (keyboard interrupt-tracking)
- Added video interrupt (HSYNC/VSYNC) initiation & 6270 return code
- Added video & sprite generation logic
- Speed up CPU emulation

Version 0.61
------------
1997/01/19
- Changed CPU clock cycle counts, and most flag updates to fit 'Develo'
  information
- Added 'set' mnemonic & altered flag-settings to set/reset 't'
- Did not check for 't' setting on affected operations (not yet known)
- Changed display of disassembly to show 'TII'-type operations better

1997/02/09
- Changed TST/TRB/TSB opcodes to set flags N & V, as per Develo
- Started improving documentation

1997/02/18
- Changed PCE color palette to use an indirection array to refer
  to a *dynamically-allocated* VGA palette (still some bugs though)
- reverted CG background code to 'C' from assembler, to integrate
  this palette code change
- Sped up sprites marginally, by optimizing the 'C' code

1997/03/02
- Changed most memory-access to use addressing-mode MACROs, mostly
  to reduce the chance of typos
- Added support for 'T' flag on affected operations
- Corrected cycle-counts for branches, and some other operations
- Fixed wrong-branch bug in BPL
- Added new interrupt-handler routines (IRQ2/IRQ1/TIMER), although
  only the video interrupt is actually referenced
- Fixed bit-width of some video registers
- Changed sprite x-positioning, and only allow 32 pixels wide
- Added support for up-down and left-right inversion of sprites

1997/03/07
- Added support for interrupt-control registers (still unsure of
  the function of $1403)
- Changed size of 'backup RAM file' to 2K from 8K
- Fixed bug in dynamic palette usage
- Added timer controller
- Roughed in PSG interface (try CMS chip interface later)

1997/03/24
- Gave up on CMS sound interface
- Implemented Sound Blaster D-A output, using mode 0x10
  (8-bit non-DMA output) for tones only (no LFO, no noise)
  - only runs at 8-bit, 7KHz mono rate

Version 0.7
-----------
1997/04/07
- Mostly sound changes:
  - allows use of DDA flag for digital samples' output
  - use master volume per voice (not just pan l/r)
  - Changed inner loop inside of Sound Blaster D-A output calc's
    to eliminate use of division
- Optimized graphics by about 30% by bit-lookup table
- Decided to migrate to DJGPP in protected mode for next version

(Yes, about a year did pass between releases...)

Version 0.72
------------
1998/06/01
- DJGPP compile done
- disabled all PC interrupt-driven activities (TIMER, sound)
- did scanline update for graphics engine
- migrated to Allegro, at least for interim period


Current known bugs/limitations:
-------------------------------
User-interface:
- Limited user-interface for debugging support

CPU:
- Memory access to unallocated segments may cause SEGV's
- should implement separate read and write mappings to more properly simulate
  read-only memory

Video:
- sprites have alignment 'bug' on some multi-cell sprites
- some video register combinations need more work

Sound:
- currently disabled

Joystick:
- Poor choice of keyboard bindings
- no support for real joysticks

Next release will probably become part of MESS (multi-console emulator)
distribution.
