FAST is an emulator written in pure 486 protected-mode assembly to be run under plain DOS.
It is intended to be emulating the Atari ST/STf/Mega ST/STe/Mega STe and Amiga 500/500+/600/1000/2000/3000 machines.
For now, it only features an incomplete emulation of the Atari ST/STf.
FAST was the first emulator to feature an emulation of the HD6301V1P at hardware level.
It was also the first to achieve fairly good redirection of floppy disk controller commands to the PC hardware floppy disk controller.
FAST Version 0.41 features the following:
Main processor (MC68000)
99%, cycle exact (except for the MUL and DIV instructions).
Prefetch queue not emulated.
Memory controllers (Glue, MMU, DMA)
Floppy disk DMA redirected to hardware PC DMA.
Memory configuration not emulated (set to 4MB).
60%, cycle exact. No serial port nor Timer B emulation.
Floppy disk controller (WD 1772)
80%, through direct PC drives redirection.
Read Track/Write Track commands not emulated.
No image disk support in this release.
Video sub-system (Shifter, etc.)
10%, approximative VBL & HBL interrupts.
Pixel drawing on access to ST screen buffer.
Sound sub-system (YM-2149)
5%, emulation of some bits of port A (floppy disk).
Registers shadowing. No sound at all.
MIDI (ACIA 6850)
99,9%, redirected to MPU-401 compatible board, UART mode,
or cycle exact ACIA faking.
IKBD (ACIA 6850, HD6301V1P, etc.)
99,9% keyboard ACIA, cycle exact.
90% HD6301V1P and connections, cycle exact.
No emulation of mouse and joystick ports inside the 6301.
FAST doesn't support Amiga emulation in its current release.
However, the first release of FAST featured a preliminary emulation of the 68000, CIAs and color registers. I hope to be able to continue this part of the emulator in some years.