How to change the FS-A1ST Disk-ROM ?

Prophet (3851)

02-11-2022, 07:41

I checked the disk ROM from the 2 4MB dumps I use for openMSX and these 2 are indeed different to C and D revisions. Most likely these are A and B revision but we need to confirm which is which. I don't have access to an A, B, E or F revision.

By gdx

Enlighted (6116)

02-11-2022, 09:42

I noticed an amazing thing. If I put a Memory Mapper (the MMM) in Slot 2, the Game Master 2 starts normally.
It seems that the Disk-Rom of the FS-A1ST has a problem with the Memory Mapper. So, sdsnatcher73 did you have a cartridge with a Memory Mapper in slot 2 (the carnivore2 for example) during your test or, was the GM2 alone?

EDIT: Disk-ROM from Turbo R has a size of 64 kB. Your files are only 16 kB. I compared with mine saved with shem, only 4 bytes are different.

mine		your
3ff5: 00	80
3ffc: FC	FF
3ffd: FC	FF
3ffF: FF	3F

EDIT2: You can use KSAVER.COM (by K.Tsujikawa) to backup the Disk-ROM.

By sdsnatcher73

Prophet (3851)

02-11-2022, 10:41

No I only had GM2 inserted. Disk ROM is just 16kB in slot 3-2 on both of my machines (I dumped the entire slot and there is only data in 0x4000-0x7fff). I cleaned out the registers to 0xFF (otherwise comparing the 2 disk roms would result in mismatch).

By gdx

Enlighted (6116)

02-11-2022, 11:49

sdsnatcher73 wrote:

Disk ROM is just 16kB in slot 3-2 on both of my machines (I dumped the entire slot and there is only data in 0x4000-0x7fff).

You forget the DOS2 Rom is mapped. Use KSAVER.COM with following parameters to dump it.

KSAVER DISKROM.ROM //s1

(With one slash you can save Disk-Rom for DOS1, with two you can save Disk-Rom for DOS2)

You can download it here:
http://www.big.or.jp/~saibara/msx/ese/mg960703-j.html