AmiMSX 4.0 is a community update of AmiMSX, the MSX, MSX2 and MSX2+
emulator by Juan Antonio Gomez Galvez (GUS Entertainment / RED Soft),
released with his permission. It is built from his v3.1 source, with parts
of his later v3.2/v3.5 source. This version puts accuracy first: many
games that broke or glitched in 3.x now run as on a real MSX.
As before, AmiMSX takes over the machine while the MSX runs and drives the
custom chips directly. HELP returns to the menu.
Beta
----
4.0 is a beta. It runs a large test set well, but some games still have
problems (see Known limits). Please report anything you find as an issue
on GitHub, with the game, the AmiMSX settings and your machine (CPU,
accelerator or emulator), so it can be triaged for the next update:
https://github.com/z00p/AmiMSX/issues
Requirements
------------
- AmigaOS 3.0 or later.
- A 68030 or better. The low-spec target is an A1200 or similar with a
68030 at 50 MHz and fast RAM. A stock 68020 A1200 runs it, but slowly.
- AGA. On ECS AmiMSX warns that it needs AGA and can carry on, with
limits, as 3.x did.
- The libraries and devices listed in AmiMSX.guide (as for 3.1).
- PiStorm (Emu68), BigMig or another fast CPU for MSX-Music (FM), 60 Hz
games at full speed and Smooth display.
Installation
------------
Copy the AmiMSX drawer anywhere and start one of the preset icons:
AmiMSX 030 68030/50 with fast RAM: PSG, PAL, sprites every frame
AmiMSX PiStorm PiStorm, BigMig and other fast CPUs: PSG+FM, display
frequency from the VDP, Japanese ID (60 Hz), audio
filter, smooth display
Each preset keeps its own settings file (ToolType PREFS=<file>), and Save
Prefs in the menu writes to the preset you started.
AmiMSX4.romcache is created next to the program on first use: each
MegaROM is hashed once and its mapper looked up in AmiMSX4.romdb. Leave
the drawer writable.
The included AmiMSX2.data is the original one (MSX, MSX2 and MSX2+ system
ROMs, disk ROM and Kanji), as in the earlier AmiMSX packages, so disk
images and MSX-BASIC work.
What's new
----------
- Z80: POP/RET through ROM, RLD/RRD on ROM, NEG/CPL flags, M1 wait
states, LD A,R from emulated time.
- VDP: sprite collisions, the 5th sprite flag, sprite mode 2 bands and
mid-frame splits (sprite tables, SCREEN 4 tables, SCREEN 5/4 modes,
palettes, R#8/R#18/R#23, display off), transparent copies, LMMC.
- MSX2+: the machine is back, with V9958 fine scroll (R#27) and the left
mask (R#25) per line (Space Manbow, Nemesis 3 Enhanced, Chikubi Ninja).
- Sound: MSX-Music (FM) on Paula channel 3 ("PSG+FM", or "FM lite" with
the 4 loudest voices); PSG volume in 3 dB steps as the YM2149.
- Display: double-buffered sprites, Smooth display (SCREEN 4) for fast
CPUs, automatic edge mask for games that scroll sideways.
- Options: Use Japanese ID (60 Hz), Audio filter, Mask screen edges
(always or auto), per-game settings next to each cartridge.
- Cartridges: ROM database (mapper by SHA-1), 8 KB, 48/64 KB and 4 MB
ROMs, flash Konami SCC cartridges with saves (Pampas & Selene).
- Disks: drive B with its own image (written back), disk swap with Left
Amiga.
- Freeware texts and no anti-crack counter, from Juan's v3.2/v3.5.
- Cleaner exits when a screen, window or device can't be opened.
See Docs/CHANGES_4.0.txt for the full list.
Known limits
------------
- Smooth display covers SCREEN 4 only; other modes run as before.
- Smooth display switches itself off in games that play MSX-Music
(FM), so their music keeps its tempo.
- MSX2+: fine scroll and the left mask only. No coarse scroll (R#26),
two-page scroll (SP2) or YJK modes (SCREEN 10-12) yet, and no fine
scroll in SCREEN 2 (Salamander Enhanced).
- Jailbreak: scenery rows flash at the top of the playfield (bitmap
splits are timed from the Amiga beam).
- Head over Heels Remake: letters missing from the menu text.
- Nemesis 2: stray cyan dots on the star field.
- Barbarian: the sky is lighter than on an MSX.
- Bombaman: moving characters look ghosted on fast machines (seen on
PiStorm and BigMig), though each frame is correct.
- Manbow 2: the intro screens are drawn corrupted, and in play the
ship jumps back 3-4 dots now and then while it moves.
- Lilly's Saga: on fast machines the save-slot menu text can be drawn
as solid blocks (seen with Smooth display off).
- Lotus F3: the car jitters while it moves (seen on PiStorm).
- CD32-style pads (e.g. KTRL CD32): a direction and the fire button
can't be held together in some games (Pampas & Selene), and the
second button may not reach the MSX (Gradius 2 power-up select).
Left Amiga (port 2) or Right Amiga (port 1) also press MSX fire
button 2; in Gradius 2 the M or N key works too.
- Gradius III Legends: it writes to its disk, so unprotect the MVD
drive. In play the scenery appears behind the ship (left) instead of
scrolling in from the right.
Credits
-------
AmiMSX: Juan Antonio Gomez Galvez, GUS Entertainment / RED Soft
(1994-2000/2009/2021).
Graphics: Multivac.
Thanks: Zener and Sandman.
Testing references: openMSX.
YM2413 instrument data: emu2413 (c) Mitsutaka Okazaki, MIT licence
(Docs/LICENSE.emu2413).
AmiMSX4.romdb: built from the openMSX software database.
Source
------
The 68k assembler source (vasm), tools and test suite:
https://github.com/z00p/AmiMSX
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