VOGONS


First post, by Ozzuneoj

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I've read about this several places on this forum but can anyone give an example of a specific game or situation that would work best for testing the hanging\dropped notes issue with the PAS16's MPU401 emulation? I recently received a somewhat less common PAS16 variant, the IXW-MEMPHIS, which connects directly to the Media Vision Memphis multimedia speaker\CDROM system with a 44pin cable (no audio jacks on the card, but there's a ton on the Memphis unit). I tested it briefly in Windows98SE because of the built in drivers and using the add new hardware wizard it installed it as a PAS16 with SCSI. The MPU401 interface seems to work normally when hooked up to my Roland SC55 (via the MIDI output on the Memphis unit), but I've only tried a couple different things under Windows 98SE. I did have some issue with the digital audio dropping out periodically in one game (Captain CLAW demo) but this happened whether the MPU401 or OPL3 were being used for music, and a Windows game from 1997 is hardly the target use for a PAS16... it just happens to be something that's installed on my tester system.

If anyone has experienced these issues with a PAS16 in the past, I'd just like to know in what games and under what circumstances they experienced issues. If a recording exists of the issue that would be incredibly helpful, since it can be hard to tell what notes are out of place if I haven't heard a given MIDI track recently.

EDIT: Some discussion of the issue from around Vogons:
486 and Roland MT32
PAS16 sounds distorted

Plus a very short anecdote to simply avoid using MPU401 on the PAS16 from Nerdly Pleasures:
http://nerdlypleasures.blogspot.com/2017/01/a … -crown-pro.html

Other than that, I haven't found much information on the subject.

Now for some blitting from the back buffer.

Reply 1 of 3, by RetroBoogie

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I tried using my SC55 under DOS as MIDI with DOOM and DOOM2, and hanging notes were really obvious. Caused me to put a separate MPU401 interface in my system. Try some DOS games.

Reply 2 of 3, by Jo22

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Ozzuneoj wrote:

If anyone has experienced these issues with a PAS16 in the past, I'd just like to know in what
games and under what circumstances they experienced issues.

Hmm.. I was a long time user of the PAS16, but had no MIDI synth back in the day, sorry. 🙁
Anyway, I vaguely believe to remember that the PAS16 uses the AdLib port as its control port (388h/389h).
In a dual soundcard test with a SB16 this caused a conflict with the SB16's OPL3 chip during init of MVSOUND.SYS:
A horrible noise came out of the SB16. Running SB16's DIAGNOSE.EXE afterwards fixed the issue, though,
and I was able to use both cards (even with the Thunderboard enabled, but on an oddball adress).
This makes me believe that the PAS16 has a special logic for its on-board OPL3,
also because the PAS16 had been designed to work with multiple sisters of its own kind in a single PC.
That being said, I didn't do much tests with the MPU-401 interfaces at the time.
I had a DB50XG on the SB16 installed, though, I believe. If memory serves, it worked fine under Descent.

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Reply 3 of 3, by Ozzuneoj

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Just wanted to bump this thread. I've had some interest in this again but haven't had time to really dig into it. If anyone has recordings or hands-on experience with this problem I'd like to hear about it.

Now for some blitting from the back buffer.