[Moved this from another thread that I posted in by mistake]
So, I've posted about my sound issued with my KT7A Athlon Thunderbird rig before. This thing hadn't, until now, worked properly as I poured well over $100 into trying to fix it. It was some ridiculously trivial oversight, but it brought my beige beast to its knees.
I was kind of expecting trouble building this rig. I was vaguely aware of the "VIA haters club", especially concerning the KT133 chipset. I didn't know about chipsets at all when I was 13, but my computer back then was a 1.6 GHz Athlon XP that ran Windows 98 (I wanted my DOS games, but I was only vaguely aware of dual booting and bought into anti-Windows XP FUD), and it was a monumental piece of shit that bluescreened daily and had to be reformatted once a year (I was a pretty terrible user back then, I admit, but it was unstable even when freshly installed). My sister's rig had similar problems and I examined a picture of her motherboard from the time (I sent it to the recyclers because she wouldn't want it and it's a sub-consumer-grade micro-ATX POS with a post-it note saying "board questionable") and it was a KT133, and mine probably was too. Also, Athlons had a tendency to run hot and had what seemed at the time to have a ravenous appetite for power. I think part of its gamer cred back then that it was better for games than the P4 for a while, but it was a loud, hot hassle with a big heat sink that normal people didn't want to deal with--it was a "gamer's processor" in both the good and bad ways. But the thing never, ever worked right. It was usually the sound card, especially when I used an external MIDI module. The sound would never work correctly, no matter how I configured things.
I discovered today that my month-plus of infuriating sound card issues were caused by one little MIDI connector. My MPU-401 breakout cable ends in not one but two MIDI plugs, one for input, and one for output. Not realizing quite how stupid DOS was at the time, I plugged them both into my Roland SC-55, because what could possibly go wrong? Everything. The bidirectional connection with the MPU-401, in DOS and DOS alone (Windows XP never, ever had problems, and I didn't even need to install drivers for any of my cards) almost always caused incredibly bizarre inconsistent, and unpredictable errors, if not outright hanging the system. I went through two Yamaha OPL3-SAx cards (which failed in different ways), ran them in parallel with a PCI SoundBlaster Live!, and now I have the AWE64. The AWE64 seemed to solve the problem, for a while, but after a few hours spent playing games with CD soundtracks, I fired up Doom and it was back, but now it just made DOS games hang on a black screen every time (and UT2004 crashed, but not in any way that hurt the system, once while I was testing it so in my state of rapidly escalating paranoia I was afraid XP was affected. I was absolutely devastated, and I was about ready to sell the motherboard and rebuild the computer as a Slot 1 machine . But while I was taking a shit this afternoon, it occurred to me, it occurred to me that perhaps the fact that the Roland SC-55 can talk back to the computer might cause problems in DOS, so I decided to disconnect the SC-55's midi out from the computer and...
It worked. All the bugs were gone. No, a fast computer does not make ISA cards useless. I was running at 1100 MHz and the music and sound were flawless. I have no idea why the computer is mesmerized into paralysis by the line to the Sound Canvas midi-out. One of the strangest bugs I've ever seen in my life. I blame VIA.