I have this board, let me know if there is interest in the Mr. BIOS from it and I can dump and upload:

Pino wrote on 2025-06-26, 20:40:

I have this board, let me know if there is interest in the Mr. BIOS from it and I can dump and upload:

yes please dump it - if possible with a programmer 😀

Pino wrote on 2025-06-26, 20:40:

I have this board, let me know if there is interest in the Mr. BIOS from it and I can dump and upload:

Oh, please do. We don't have this version currently, it's a pretty common chipset and it's a pretty recent version.

keropi wrote on 2025-06-26, 20:59:

Pino wrote on 2025-06-26, 20:40:

I have this board, let me know if there is interest in the Mr. BIOS from it and I can dump and upload:

yes please dump it - if possible with a programmer 😀

Unfortunately I don't have a programmer, what is the next safest way to dump it in DOS?

This should work--

1DEBUG.EXE
2N MRBIOS.BIN
3R BX 
41
5R CX 
60 
7W F000:0
8Q

should look like this when you run it:

1DEBUG.EXE
2-N MRBIOS.BIN
3-R BX 
4BX 0000  :1
5-R CX 
6CX 0000  :0 
7-W F000:0
8Writing 10000 bytes
9Q

fyi: 10000 bytes = 64KB

Thanks!

Here it goes, I made 2 copies one using your DEBUG instructions and one with the NSSI software mentioned on the first page of this thread.

Hopefully it works.

Ps.: Amazing that this old 486 VLB board with this BIOS booted DOS from my 32GB SD card.

both of those binary files in the archive are identical

fyi you can use the DOS command FC /B to do a binary compare

Pino wrote on 2025-06-27, 01:54:

Thanks! […]
Show full quote

Thanks!

Here it goes, I made 2 copies one using your DEBUG instructions and one with the NSSI software mentioned on the first page of this thread.

Hopefully it works.

Ps.: Amazing that this old 486 VLB board with this BIOS booted DOS from my 32GB SD card.

Thank you so much!

I quickly tested it in 86box, seems to work just fine, will be testing on real hardware eventually.

Anonymous Coward wrote on 2020-05-02, 13:45:

I tried SiS Rabbit, C&T Peak/DM and Topcat MR-BIOS. None of them can enable the cache on the boards. It's kind of disappointing because these are all high performance chipsets that could have really benefited from MR-BIOS tweaks. Only the Topcat chipset can be excused, because this chipset doesn't natively support cache...that comes from a 3rd party controller.

Question to rather old post, but here it goes.

I recently obtained Octek Jaguar 386 motherboard. It is the first Jaguar released around 1990, so not later Jaguar II or Jaguar V. It is equipped with Rabbit chipset and 64k cache on the mobo. I burned the MR BIOS Rabbit BIOS for the chipset and to me it seems to work just fine. However, if I use something like NSSI, it claims that there is no cache even though cache is enabled on the bios, but CACHECHK utility shows the cache just fine. Performance is also right about there where I expect a 33MHz DX to be that is installed on the board.

So what did you use to verify that cache is not enabled on boards with MR BIOS?

I observed the speedsys memory graph and benchmarked with 3dbench. The cache was definitely not working.

Anonymous Coward wrote on 2025-07-23, 23:34:

I observed the speedsys memory graph and benchmarked with 3dbench. The cache was definitely not working.

Yeah. Maybe my chipset is then after all some later revision then. It would be interesting to know why it works with some Rabbit boards, but not with others.

Do you know how the turbo is handled with your mobos, because that is one thing that could be different I suppose. My mobo has both the physical and software turbo with keyboard and you can set the turbo in MR BIOS for default system setting. The turbo in my board just disables or enables the cache. In other words, when the system is se to high speed in MR BIOS, cache is enabled and vice versa. If your mobos have different type of scheme, the turbo setting in bios may affect to cache operation. MR BIOS seems to have few different BIOS versions for different turbo schemes, but you probably tested them all.

I’m pretty sure the turbo on my board also toggles the cache. It’s something I could look into again, but this board isn’t high priority for me at the moment as it fails to POST when DLC/SXL cpus are installed. It’s odd as my board supports hidden refresh.

Anyone notice those new old stock Seanix ASI 9000 486 computers getting sold on ebay canada?

They have MR BIOS 1.60 OPTI4A7. That’s one that’s not on the lists.

hi, someone have the Sarc RC2016 ?