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Formac ProNitron 80.21 Nubus ROM wanted


Well-known member
@demik sent me this card to take a look at why it's not working:


It does not show up in TattleTech/SlotInfo... turns out the ROM is bad giving mostly garbage when dumped.

So a "simple" request to get this card back to life: Anyone has a card like that and can get me a dump of the ROM?


Well-known member
Oh well, that was an easy one... thanks to @cheesestraws who looked at the corrupted dump and could tell in the blink of an eye that it was bit 4 that was stuck high.
I tried to read the ROM again with different pulldown resistors on the corresponding data pin of the corrupted ROM chip and would actually get a consistent reading from the chip with what looked like non-garbage data.

Calculated the checksum of the dump and it matched, burned a new EPROM and lo and behold the card just sprung to life.
Now that was a quick and fun repair.


  • Formac ProNitron80.21 V1.1.BIN.zip
    2.8 KB · Views: 2
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Well-known member
Nicely done. Very cool work.

Indeed they did a nice job !

Since there is almost no documentation on this card, here is what we found:
- The card output a fixed resolution of 1152x864@ 78 Hz
- Without the ProMem board it's only 8 bpp, with the ProMem memory board, the output is 24 bpp
- It need 32 bit mode to display all colors
- It was sold between 1991 and 1992.
- There was a sister card, the ProNitron 80.19 which had lower specs (supposed 1024x768 ?)
- The card does not have any framebuffer chip. The only speciic chips are the RAMDACs