First post, by VileR
- Rank
- l33t
Picked this up locally. The seller had used it ages ago, and as far as he can remember, it was an MDA-type board (monochrome, but no graphics).
He isn't sure though... and there are two RCA outputs which might indicate CGA. It's certainly not EGA or anything that would use them as "feature connectors".
The only identification on this is "MADE IN TAIWAN" (nothing whatsoever on the back side).
Click for hi-res pics:
The seller also has an EPROM reader, which I don't, so we also tried to get a dump of the character ROM. Problem was, there's no visible text on the chip and we didn't know the type.
Standard (IBM-type) CGA/MDA uses a 9264 ROM (64 Kbit), but his reader didn't have that option. Instead we made two read attempts, one as a 2716, one as a 2532.
The 2716 dump gave a 2K binary containing one 8x8 font:
The 2532 dump gave a 4K .bin with a different (thin) 8x8 font, followed by 2K of FF bytes:
So far that's consistent with CGA. But many MDA boards (including IBM's) still contained the unused 8x8 fonts, alongside the MDA's 8x14.
For all I know, it COULD be a 8K chip, and both of these reads simply missed the relevant 4K of data. For those who know their way around EPROM types - given the above dumps, is that a possibility?
