kolibrios/programs/emulator/dgen-sdl-1.33/musa/history.txt

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The history of Musashi for anyone who might be interested:
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Musashi was born out of sheer boredom.
I needed something to code, and so having had fun with a few of the emulators
around, I decided to try my hand at CPU emulation.
I had owned an Amiga for many years and had done some assembly coding on it so
I figured it would be the ideal chip to cut my teeth on.
Had I known then how much work was involved in emulating a chip like this, I
may not have even started ;-)
12-May-1998: First outline
11-Jun-1998: Early disassembler
20-Nov-1998: First prototype v0.1
04-Dec-1998: Final prototype v0.4
20-Dec-1998: Beta release of Musashi v0.5 that could run Rastan Saga under MAME
(barely).
06-Jan-1999: Musashi 1.0 released
17-Mar-1999: Musashi 2.0 released
- Major code overhaul.
- Replaced monolithic codebase with a code generator program.
- Added correct m68000 timing.
- Moved timing into the opcode handlers.
25-Mar-1999: Musashi 2.1 released
- Added support for m68010.
- Many bugfixes.
13-May-1999: Musashi 2.2 released
- Added support for m68020.
- Lots of bugfixes.
05-Apr-2000: Musashi 3.0 released
- Major code overhaul.
- Rewrote code generator program and changed the format of
m68k_in.c.
- Added support for m68ec020.
- Removed timing from the opcode handlers.
- Added correct timing for m68000, m68010, and m68020.
Note: 68020 timing is the cache timing from the manual.
- Removed the m68k_peek_xxx() and m68k_poke_xxx() instructions and
replaced them with m68k_get_reg() and m68k_set_reg().
- Added support for function codes.
- Revamped m68kconf.h to be easier to configure and more powerful.
- Added option to separate immediate and normal reads.
- Added support for (undocumented) m68000 instruction prefetch.
- Rewrote indexed addressing mode handling.
- Rewrote interrupt handling.
- Fixed a masking bug for m68k_get_reg() when requesting the PC.
- Moved the instruction table sorting routine to m68kmake.c so
that it is invoked at compile time rather than at runtime.
- Rewrote the exception handling routines to support different
stack frames (needed for m68020 emulation).
- Rewrote faster status register and condition code flag handling
functions / macros.
- Fixed function code handling to fetch from program space when
using pc-relative addressing.
- Fixed initial program counter and stack pointer fetching on
reset (loads from program space now).
- A lot of code cleanup.
- LOTS of bugfixes (especially in the m68020 code).
28-May-2000: Musashi 3.1 released
- Fixed bug in m68k_get_reg() that retrieved the wrong value for
the status register.
- Fixed register bug in movec.
- Fixed cpu type comparison problem that caused indexed
addressing modes to be incorrectly interpreted when in m68ec020
mode.
- Added code to speed up busy waiting on some branch instructions.
- Fixed some bfxxx opcode bugs.
14-Aug-2000: Musashi 3.2 released
- Fixed RTE bug that killed the program counter when in m68020
mode.
- Minor fixes in negx and nbcd.
- renamed d68k.c to m68kdasm.c and merged d68k.h into m68k.h.
d68k_read_xxx() instructions have been renamed to
m68k_read_xxx_disassembler().
- Rewrote exception processing and fixed 68020 stack frame
problems.
- FINALLY fixed the mull and divl instructions.
- Added 64-bit safe code fixes.
- Added 64-bit optimizations (these will only be ANSI compliant
under c9x, and so to use them you must turn on M68K_USE_64_BIT
in m68kconf.h).
27-Jan-2001: Musashi 3.3 released
Note: This is the last release of Musashi before I separate the
68020 core.
- Fixed problem when displaying negative numbers in disassembler
- Fixed cpu type selector - was allowing 020 instructions to be
disassembled when in 000 mode.
- Fixed opcode jumptable generator (ambiguous operators in the
test for f-line ops)
- Fixed signed/unsigned problem in divl and mull opcodes (not
sure if this was causing an error but best to be sure)
- Cleaned up the naming scheme for the opcode handlers
02-Feb-2001: Musashi 3.3.1 released
Note: due to the pc-relative requirement for some new drivers
in MAME, I've released this small update.
- Added pc-relative read modes
- small optimizations to the exception handling that will help
when splitting the cores
- Updated the example (oops!)