digistorm wrote on 2020-05-23, 17:35:
Okay, well I notice with my GUSpnp that after certain programs (mainly demo's) that maybe don't exit clean, that after that samples sound staticcy (if that is a word) or that the loop points are not accurate.
I have never read about this bug being triggered by software that doesn't exit cleanly, though I'm not sure anyone ever documented a simple, reliable way to demonstrate the bug. It also doesn't exactly sound like static to me.
It is worth repeating that the InterWave also behaves somewhat differently from a traditional GF1-based UltraSound. Because of the different clock frequencies used with the InterWave, as well as the way the compatibility is implemented, the playback rates will be slightly different than what you would get on a real GF1-based card (when using UltraSound compatibility mode). That could affect loop points. The "distortion bug" is different in that, once triggered, it affects all modes of operation, and the audible differences are present in InterWave enhanced mode (even when using the included PLAY.EXE to play MOD or MIDI files), and persists until a full power cycle. If what you are noticing is resolved by running IWINIT or different software afterwards, then we are not talking about the same thing.
digistorm wrote on 2020-05-23, 17:35:
Especially with smooth samples like sine waves or pads you hear tics at the loop points that shouldn't be there. I didn't know if that was normal, and I wonder if it is related to this 'bug'. My GUSpnp has a version number 1.0 on the PCB and the Interwave chip has the year 1995 on it.
As far as I'm aware, all InterWave chips have a 1995 copyright engraved into the chip; the chip used on my first ARGUS prototype was produced in 1996, but the copyright is still 1995. Also, I have never noticed the bug on a board that uses the AM78C201AKC; only those without the 'A'. Furthermore, it seems to affect earlier parts with a 1995 production code; for instance, mine is 9541EGA B2. Some old discussions have suggested that is is the Bx notation that suggests an affected part.