IBM PGC graphics card for 5160/5170 currently working in .275? Get blank screen.

[trguhq]

Anyone know if the PGC driver is working? I put it in first slot, set the DIP to EGA/VGA. Pick the latest XT BIOS for 5160 (default). The system seems to boot (beeps after a bit, boot sounds) but nothing is displayed. Anything I try with PGC on 5150/60/70 I get blank screen. Thanks.

[angelosa]

Did this ever worked to begin with? As if it's expecting a standard EGA/VGA card as companion of the PGC.

[angelosa]

Sounds like it wants a BIOS then, lemme guess: is it the part that is currently unused by the core device? Has 2 x 32kB ROMs, only second one is used.

[cuavas]

It did work to some extent at one point, but the CGA emulation was never implemented IIRC. You needed to install it alongside a CGA card. The trouble is it’s one of those things hardly anyone uses, so if it broke, people won’t notice for a while.

Information on emulation status is here (updated 2019, so it may have broken since then): https://wiki.mamedev.org/index.php?title=Driver:PGC

[angelosa]

ibm5150 / ibm5160 just don't boot, that's without the pgc card.

[angelosa]

After further analysis it looks like ibm5150 just returns a 52 301 from time to time locally (a non-fatal keyboard warning). ibm5160 is just broken and refuses to boot.

So, in order to answer OP: ibm5150 isa default mapping is cga / com / fdc_xt / hdc / <empty_slot>. That means, at minimum usable terms the pgc should be mounted at either -isa5 or (if you don't need serial port) to -isa2.

[trguhq]

Thanks. I have a real PGC card so I wanted to see if I could test software for it in an emulator without putting too much stress on the real thing, as it is old, valuable, and possibly fragile (and already needs one electronic repair at least).

Theoretically I would be interested in helping getting this all working in MAME, but I have a number of projects on the table so it may be some time before I can dive into this. I had considered trying to pull the PGC emulation code from MAME and plug it into a more reliably working PC emulator, but even that, realistically, may be a substantial project.

[trguhq]

It is working, at least mostly. It successfully displays a 256 color bitmap, however it does fail the IBM diagnostic, with reference to a specific chip I believe. The diagnostic is pretty exhaustive and might help refining the emulation. I can't update the Wiki (waiting on my account to be validated) but there is some more software out there, specifically John Elliott's PGCBMP and PGCTALK test utilities. I will update the Wiki when I can.