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Identifying an 8-bit ISA graphics card (Paraside PEGA2 chipset)

M

MindWalker

Experienced Member
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Jul 23, 2019
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Helsinki - Finland
Hi.
I got this ISA card inside a Commodore PC10-II that I just bought. Can anyone recognize this graphics adapter? It looks quite a bit like this but the connections are in slightly different locations and the jumpers don't quite match.

Mainly I'd need to know how to configure the DIP switches and wheter I can get a composite video output from the two, non-marked, RCA-connectors. (The PC itself is working, tested with another VGA board). Could I use this in some configuration to connect to my Commodore 1084S monitor?

The main chips are:
  • Paradise 38305 PEGA2
  • Paradise LIA2920
  • EPROM PDPE 5.28 (27C256)

On the top-left corner it says "(C) 1987, Dec 2, Assy 22200, Rev 3.31)

 
If your 1084S is one of the ones that supports TTL RGBI, yes, I'm pretty sure it can be wired to the card using the DIN connector, and the card can use it as a CGA monitor with no brown, or EGA with restrictions (no 350-line mode, no 6-bit color modes).

As Stone points out, you won't be using the composite video input with that card either.
 
I think I found it!

I dumped the EPROM and it started with "Copyright OLIVETTI 1986 IBM EGA & CGA COMPATIBLE rel. 5.28 date: 09/04/87".

Ok, I started googling with Olivetti, and then I came across this eBay ad and yes, that looks identical! Some more googling with the newly found ID of Olivetti GO467 and then I found this PDF document where on page C-5 the right-handside drawing matches exactly the parts on my board!

There is a jumper P3 which "Composite signal sent to J1" so it looks I might indeed have composite video output! Also now I can check all the DIP settings, great!
 
I stand corrected, and a reminder to myself that "almost none" is not mathematically equal to "none at all".
 
Hmm, still not quite there yet...

I have set the board for primary adapter, cga emulation, and connected it to my C1084s monitor with an EGA-TTL RGB cable. I had gotten this cable among some C64/C128 cables, and this seems to be the same cable as the one used with C128's 80-column mode.

I am getting a recognizable Commodore PC Bios screen, but it's not stable.

If I have the P4 jumper set to 24 MHz oscillator selection (default), I get a picture that rolls both vertically and horizontally:


If I set the P4 jumper to 14 Mhz mode, I get a picture that rolls (only) in vertical direction:


I have tried setting the motherboard video mode jumper to all modes, but none gives me a stable picture, just variations of these two issues. Also setting the card to autoswitch mode did not help.

This is not really that much of an issue as I will most likely use the computer with a VGA card, which works perfectly fine. But for testing and historical purposes this would be an interesting card to use with the 1084s.
 
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