Spending some more time on this I tested numerous theories. It came out that simm module was working correctly while problems were visible (or rather hearable) with onborad ram only. Keeping it short I found that in some case memory writes were wrong. Sometime bytes were written in the wrong address …

@Rawit I tried it on 2 different pcs. The BX boards, compaq with very poor bios (very limited settings) and the other one wth regular Ami or Award BIOS. I played with what I could, but always the same, thus I think its not related to ISA settings. Regardinng the toslink transmitter. I have a plan to …

Thanks a lot to both of you Rawit and 640K!enough for your help. Now knowing there is something wrong with my card I can justify more time spent on troubleshooting. My card is essentially clone of Argus. I was too late to participate in Argus project, but thanks to __shock who published the …

I tried with ULTRINIT, but it didn't help. I also know this thread from Pouet, but as I understand it (maybe wrong) it would generate the noise until pc is restarted, which is not my case. The Fulcrum has a config file in which these 3 options regarding the GUS can be selected: ;gus parameters gus_ …

The card is more similar to Philips one. I flashed it with Gus PnP firmware. I tested it with 3 sets of ram in total (2 different sets of onboard ram and a simm module) thus I would say memory is ok. The RAM access time was 60ns. It had 1MB or more, depending on the config.

I have GUS PnP clone card with AMD AM78C201AKC chip. The original (red) GUSes PnP were built with AM78C201KC and I owned one of them years ago. If I remember correctly it had some compatibility issues in GF1 emulation mode, but after decades I don't remember exactly what was wrong. Nevertheless, I …

Hi, First of all respect to all contributors to this project. I found it kinda late so had no chanse to contribute early enough to be eligible for a proptotype. Also, as I got from reading the thread, the number of AM78C201AKC is limited and reserved for the contributors. I was wondering if there …