All

I'm in the process of trying to get my 1990 MH600E up and running. As part of that work I'm going thoroughly through all cards inside the 423 controller.

When taking a closer look at my graphics card I noticed that the PROM's on there mention both GR2P and GR8P. And I can't help but wonder what it would take for me to upgrade it to be able to show GR8P. This is the full text on the 4 PROM's:
"
67**.700/05
GR2P D19 (D on the first chip, C on second, B on third and A on the forth chip)
GR8P D55 (A on the first chip, B on second, then C on third and forth chips)
"

This makes me believe it would be possible to upgrade from GR2P to GR8P level graphics. Assuming this mode needs more memory it’s then safe to assume this is what the empty slots along the RAM chips on the card is for. The address lines on these sockets seem to be shared with the already installed RAM, so this seems to me like a possible scenario.

I checked, and found the RAM chips (TMS 4164-15NL) for $2.30 each for 11 or more online. This seems like a cheap way to upgrade the graphics capabilities of my mill.

But then again, is it worth it? Is there a real benefit of doing this? And is it the correct way to do it? And would it need jumpers to be moved around for it to work?

Is there anyone out there with GR8P capable machine that would be willing to check their hardware to verify if this is doable, and what needs to be done? I have pictures (but not easily available where I'm at now) of this. What would be great is if someone with GR8P graphics could post similar pictures of their card so we could compare.

Or if somebody actually have the upgrade procedure and know exactly what to do.

Anders