Feasibility Study: VRAM upgrade of 1/2 HPV VidCard to 2/4 capability.

[Trash80toHP_Mini]

I've been in touch with a member who should know and he thinks this might be worth looking into. I've got examples of Apple's HVP 1/2 card and have compared it to my Power Computing HPV 2/4 card. The board layout is very different, but components are the same with RAMDAC, ROM and ASIC being identical Apple parts but for designation differences minor enough to reflect the 2-3  years different production/copyright dates on the two cards.

I've hit a brick wall because I nave on Apple 2/4 HPV Card for comparison. It shipped in the higher end 8100 configurations if memory serves. Could someone upload High Res pics of the Apple card for comparison to the 1/2 boards I have on hand? 'fritter's NuBus Mafia has pics of the AV card, but none of the HPV cards that I could find. That would be a fab place to do the upload.

Here's the pic of my PowerComputing 2/4 HPV Card for reference if you're scouring eBay for the like:

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Help with pics would be much appreciated. Just really curious about it at this point, bit crazy cool thing to try if the prospects look good.

 

[Franklinstein]

Do you have any specific model numbers for the card you're after? I have a few HPV cards, including a couple out of 8115/110s, but I can't be sure they're the high-capacity version you're after.

 

[Trash80toHP_Mini]

I was told the part number for the Apple 2/4 HPV card is 820-0509-a, my Apple 1/2 HPV card is 820-0522-A, but that's only a designation on the silk screen layer. Copper etch on solder side reads:   M1   94-0  T204  the "204" is in an italic stencil font and the whole thing is likely the board number/run info etc, dunno.

Bt9055 RAMDAC 100 and ASIC appear to be the same with only minor designation changes.

ROM version is 9515 on PC 2/4 and 9491 on Apple 1/2

The capacity of the VRAM ICs on a card is probably the easiest way to tell for sure, but I'm too tired to dig my cards out again to look.