Hello everyone and happy new year!I have a question about games specific to the Apple IIgs. I have colours flashing on the screen when I run several games, like Lemmings, Wolfenstein3d or DejaVu. I first thought it was my TranswarpGS, my RAM expansion or my computer itself, so I tried it on another IIgs, with the same result.
https://imgur.com/w2HrKpg
Then, totally by chance, I found a program called GC.noSS.SYS16, which, when I run it, trash the screen.
https://imgur.com/9QK7ojz
I did a keyboard reset, and the games run without any graphical bugs after that. I don't understand what this is about, does anyone have an explanation?
https://imgur.com/SLRxV0G
thanks!
I wonder if it could be a VGC issue
Some of the earlier IIgs had defective VGC chips and there was free replacement of it and the ROM available for a number of years.
Thanks for your reply.
The problem is that I have the same behavior on 2 different IIgs, can it be that both have this defective chip?
The part numbers of the defective VGCs are AMI 344SOO46-1 and 344SOO46-A . All others are good
Thanks. I just checked, I have a AMI 344SOO46-2, so it's not the problem.
I'm launching those games from the desktop, can it be the problem?
Yes, most all games were made to boot from their disk with their own version of the OS. What happens when you launch from your own environment can vary...
Your are right: I booted Lemmings from the floppy disk, and the flickering isn't present. It's purely a software problem.
Thanks for your help all :-)