Small Wonder Graphics ROM missing

[NeXT]

I remembered I had one of these and was holding onto it until I had a suitable machine. On my card at least the chip in U2 is missing. Google says there should be a 9864ADS ROM sitting in that socket and my money is that it's the video BIOS and the card is useless without it.

I can't find any really detailed information on the chip but am I safe to assume it's compatible with a 2764/27128 EPROM and if so, does anyone have a copy of the ROM so I can reuse this card?

 

[Chuck(G)]

I believe that U2 was a socket for a second character set. Not all Small Wonder boards were supplied with the ROM (or the composite video output):

 

[FishFinger]

CGA cards don't have a video BIOS. The socketed ROM (U1) contains the fonts used by the card in the various text modes. If there are any other unpopulated chips then they're either optional extras, or different manufacturing options (so the manufacturer had the choice of using a DIP in U1 or a surface mount chip in U2 for the font ROM).

I've got a card identical to the one Chuck posted. I can dump the socketed ROM in U1 if you need it.

 

[NeXT]

I guess you could dump it for completeness sake but it makes me wonder: Is it possible to add your own modified character sets?

 

[FishFinger]

There are three fonts - the normal 8x8 CGA font, a thin 8x8 font possibly used in the 132-column modes the card supports, and an 8x14 font for the mono modes.

 

[NeXT]

Oh yeah, that's the ticket. Thanks.

 

[Robin4]

And does the card work?

 

[NeXT]

Well.....the results are rather mixed.
I'll continue working on it in that new thread as my problems no longer appear to be an issue with the chip, unless it's really not liking me using a 27128 EPROM.

Edited: In case someone in the future can't link to the second page, YES, this is the character ROM and it needs to be properly burned depending on the size chip used. The chip being missing or improperly burned will result in a garbled output.