That's the Biostar logo on those chips. Looks like it's one variation of an MB-1212V

jakethompson1 wrote on 2025-09-30, 00:43:

That's the Biostar logo on those chips. Looks like it's one variation of an MB-1212V

Thanks a lot, i need this 😀

renejr902 wrote on 2025-09-30, 00:03:

Hi! I have a rare 286 motherboard: R.O.C Rev-B.6.

I don't want to get into the political backgrounds, but you should be aware that "R.O.C" is part of the country name "Taiwan R.O.C" in the sentence "Made in Tawain R.O.C", and not part of the mainboard model name. The letters mean "Republic of China", contrasting PRC (the "People's Republic of China").

renejr902 wrote on 2025-09-30, 00:03:

Maybe it has a jumper for vga vesa bios card like ibm xt 8088.

In fact the PC/XT had a DIP switch to choose between the MDA support integrated into the mainbaord BIOS, the CGA support integrated into the mainboard BIOS or a video card with dedicated BIOS (although there was no VESA yet). The AT moved the DIP switch into the CMOS setup RAM. So if you have a CGA card, you might want to try running BIOS setup utility (from floppy, e.g. use GSETUP or integrated into the BIOS) to select the "video card with dedicated BIOS" mode. Most AT-like boards automatically detect this situation and run using the VGA card if set to "CGA" (Color 40 or Color 80), but possibly some early BIOSes didn't.

Many VGA cards don't work on 286s because the extra addresses LA 17 - 23 aren't buffered/latched. Some VGA cards have workarounds, some only work at the basic 8MHz ISA clock.

Tseng ET3000/4000 cards may have a good chance of working

8bit'ified tridents might as well. Wont win any speed competitions, but beggars arent choosers

mkarcher wrote on 2025-09-30, 07:17:

I don't want to get into the political backgrounds, but you should be aware that "R.O.C" is part of the country name "Taiwan R.O […]
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renejr902 wrote on 2025-09-30, 00:03:

Hi! I have a rare 286 motherboard: R.O.C Rev-B.6.

I don't want to get into the political backgrounds, but you should be aware that "R.O.C" is part of the country name "Taiwan R.O.C" in the sentence "Made in Tawain R.O.C", and not part of the mainboard model name. The letters mean "Republic of China", contrasting PRC (the "People's Republic of China").

renejr902 wrote on 2025-09-30, 00:03:

Maybe it has a jumper for vga vesa bios card like ibm xt 8088.

In fact the PC/XT had a DIP switch to choose between the MDA support integrated into the mainbaord BIOS, the CGA support integrated into the mainboard BIOS or a video card with dedicated BIOS (although there was no VESA yet). The AT moved the DIP switch into the CMOS setup RAM. So if you have a CGA card, you might want to try running BIOS setup utility (from floppy, e.g. use GSETUP or integrated into the BIOS) to select the "video card with dedicated BIOS" mode. Most AT-like boards automatically detect this situation and run using the VGA card if set to "CGA" (Color 40 or Color 80), but possibly some early BIOSes didn't.

Ok inhave the option in bios to choose vga/egwla or cga. still its a no for my 3 isa video card. But the trident has jumper option to work in 8 bit, i will try that now. Thanks ( i dont have any tseng ) ( my others computer build have isa video card, i can remove card in them and try ) i will let you kmow

wierd_w wrote on 2025-09-30, 15:39:

8bit'ified tridents might as well. Wont win any speed competitions, but beggars arent choosers

Finally i got it working.

Trident 8900D doesnt work in 16 bit or 8 bit with jumper in 8-bit

Cirrus-Logic dont work

Oak Oti-067 WORKS in 8-bit or 16-bit.

It's fine.

My goal in future is to put a ega card and buy a ega monitor. When i can find one at a reasonable price.

Thanks guys for the help

renejr902 wrote on 2025-09-30, 18:53:

Trident 8900D doesnt work in 16 bit or 8 bit with jumper in 8-bit

Cirrus-Logic dont work

Oak Oti-067 WORKS in 8-bit or 16-bit.

Wow, that sounds very picky. There are known incompatibilities between certain IDE devices (especially IDE-CF adapters) and 16-Bit VGA cards, regarding the ALE signal. As the ALE signal is part of the 8-bit connector, using an 8-bit slot doesn't fix the incompatibility, even if ALE is mostly used to handle 16-bit stuff.

If you are interested in getting that TVGA8900D working (it is supposed to be significantly faster than an Oak 067), you should try whether it works better without any IDE device connected. If yes, we can think about countermeasures.

mkarcher wrote on 2025-09-30, 19:45:

renejr902 wrote on 2025-09-30, 18:53:

Trident 8900D doesnt work in 16 bit or 8 bit with jumper in 8-bit

Cirrus-Logic dont work

Oak Oti-067 WORKS in 8-bit or 16-bit.

Wow, that sounds very picky. There are known incompatibilities between certain IDE devices (especially IDE-CF adapters) and 16-Bit VGA cards, regarding the ALE signal. As the ALE signal is part of the 8-bit connector, using an 8-bit slot doesn't fix the incompatibility, even if ALE is mostly used to handle 16-bit stuff.

If you are interested in getting that TVGA8900D working (it is supposed to be significantly faster than an Oak 067), you should try whether it works better without any IDE device connected. If yes, we can think about countermeasures.

Tomorrow is a wonderful day, i will buy a ega monitor in my city. The seller reserved it for me. I want to put it with this 286. BUT my oak oti037c isa video card, with dual output with ega, doesn't work too on the 286 and beep. I tried it in 8 bit slot, 16 slot, switch to cga and to vga, nothing work sadly. I want this card because i want to connect the ega monitor on it. Do you have any idea ? The hdd is a 2.5 44 pins ide drive of 800mb formatted to 504mb to work with the 286. ( i use a ide 40 pins to ide 44 pins adapter, it works great, i played a lot of game, no bad sector )

I have a 1.2mb and 1.44mb drive both works great.
But i need the oak 0ti37c to works in this system. i dont want to use a ega monitor on a 386.

( i also have a Ati VGA wonder+ with dual output for ega. But this card need repair, i just got it, but it doesnt work or boot, my electronic technician father will check it tomorrow and try to repair it.

Thanks for any idea for the oak oti037c

I wonder if it's some problem with the video BIOS on some of these cards versus the video RAM or i/o ports. Do you have any other cards with option ROMs? What is that card in the top slot that looks like it has a blue barrel battery on it, as if it's an XT clock card?

jakethompson1 wrote on 2025-10-01, 04:13:

I wonder if it's some problem with the video BIOS on some of these cards versus the video RAM or i/o ports. Do you have any other cards with option ROMs? What is that card in the top slot that looks like it has a blue barrel battery on it, as if it's an XT clock card?

it was a Ati cga card, that works with it. Small wonder solution version 1.

the other card is a multi i/o card with fdd and hdd port, gameport, printer port, serial...

the blue barrel is the battery that is still works and save bios. i should do a battery mod, i didnt check yet if it was a battery that can leak.

( on the picture from the front of the computer one of the two 1.44 floppy drive is not connected at all, its there just for the look. )

Does the OAK OTI-037 work in another PC? Sometimes reseating the BIOS chips (and other reseatable chips) works due to oxidisation on the pins.

MikeSG wrote on 2025-10-01, 18:12:

Does the OAK OTI-037 work in another PC? Sometimes reseating the BIOS chips (and other reseatable chips) works due to oxidisation on the pins.

yes the card works in all others system and i have several system. I got my ega monitor. i paid 200$canadian for it. Nec multisync plus monitor. on my 386 the oti037c works perfect in ega with the monitor. i will buy a 8 bit ega card for the 286