8bit Friendly ISA VGA cards

[Moogle!]

I would like to add 3 cards I have confirmed to work in 3 different 8 bit systems. These were not extensively tested beyond booting into DOS 6.22. The systems tested were an IBM XT 5160 with the 1982 BIOS; a Hedeka 919, which is an odd 286 based XT with only 8 bit slots and a switchable 10Mhz / 4.77Mhz mode; and an XI 8088 in a third party backplane that is all 16 bit slots with BIOS 0.9.9.

There is a Video Seven VEGA VRAM, an OEM Trident Board, and an Everex with the Accumos AVGA1 chipset. The Video 7 card needs switches 6 and 7 to be in the off position, the Trident and Everex seem to autosense. I have found that using the XI8088 with the 16 bit backplane seems to throw off some cards, such as one of the ATI VGA Wonders.

 

[Moogle!]

Something to beware of, just because the chip supports 8 bit mode doesn't mean the card does. Here are two cards I cannot get to work in any of the three systems mentioned in the preceding post. I am reasonably certain The Oak 0TI037C card simply does not appear to support 8 bit mode despite the datasheet mentioning PC support.

I am not certain what all the switches on the Cardinal do, since there is no documentation to be found anywhere, but the switches are in the state I received it in, and it does not show a display in an 8 bit slot.

 

[Eudimorphodon]

Oak 0TI037C card simply does not appear to support 8 bit mode despite the datasheet mentioning PC support.

The *only* thing that's 16 bit on an OTI-037 card is BIOS access. I mean, literally, that's it. The VGA itself is *entirely* 8 bit. If one of those jumpers doesn't set 8-bit mode then maybe this one is trying to autodetect and failing?

 

[Moogle!]

The *only* thing that's 16 bit on an OTI-037 card is BIOS access. I mean, literally, that's it. The VGA itself is *entirely* 8 bit. If one of those jumpers doesn't set 8-bit mode then maybe this one is trying to autodetect and failing?

VP42B

www.uncreativelabs.de

It would seem none of the jumpers control 8 bit access. I know my 067 card had jumpers that had to be changed.

 

[Eudimorphodon]

Looking at the photo of the card it’s… weird. Found another set of front and back photos here:

VGA Legacy MKIII - Oak OTI-037C

Basic VGA controller. Palcal's cards: Vlask's cards: Zaatharen's...

vgamuseum.info

And… I know this is probably a multi-layer circuit board, so there could be traces buried, but it almost looks like there aren’t any traces running from the 8-bit side of the board to the ODD ROM chip’s data lines? (there are address lines bridged over) Unless there’s another set buried in there it almost looks like this card may well be “obligated” to run in a 16 bit slot?

FWIW, that would be a terrible design choice. It’d likely cause conflicts with any other card you might install that has 8 bit BIOS ROMs.