The thing you have to keep in mind with the PC-98 series, at least in terms of audio, is set the way it is because Japenese developers embraced FM Synthesis in ways that American developers didn't. This means that much of their FM music sounds way better than the vast majority of Midi music and FM music on Western DOS machines. Also, the YM2203 of the earlier units was really a more dynamic and interesting chip in so many ways than the YM3812. While limited to three FM voices, it was capable of 4 operators off that bat, whereas DOS computers didn't see anything like that until the YMF-262. Even then, extremely few ever used 4 operator synthesis in standard MS-DOS. Also, it had a PSG based on the AY-3-8910 used in previous computers like the Sinclair ZX-Spectrum, and countless other arcades and computers. That alone produces a type of sound that FM can only emulate. Then NEC used the YM2608 which could play samples. That really killed much of a need for anything like a SoundBlaster for most PC-98 games. It basically upped the FM voices/channels to 6, kept the PSG, added 6 voices for preset percussion, and added a single voice for whatever the program needed. This actually far outstripped the sound capabilities of even the Sega Genesis/Megadrive, which was still quite popular well into the 90s. That was more than enough for most of the games that would run on hit. Even the original SoundBlaster really didn't do much better when you consider that few if any developers actually used the sample playback for music that wasn't just generated using the CPU. They just let Midi handle that. What need was there for a SoundBlaster card for 90%+ games that would be running on this platform?
The Sega Genesis/Megadrive's YM2612 is actually a cut down version of the YM2608 used in the PC-9801-86 sound board and the Sound Board II for the PC-88. Doesn't have the PSG channels (though the MD contains a separate SegaPSG for Master System compatibility) and PCM precussion channels, but other than that it's about the same. A lot of composers in Japan also used PC-88s to write and arrange music for Megadrive games, notably Yuzu Koshiro.
The graphics in Japanese games of that era were so good. Consoles like the SNES simply didn’t have the resolution needed and the artsyle for manga of that era was very good. But as I don’t read Japanese most of those games I will never play.
You could've just used a Voodoo pass-through cable to avoid the VGA cable switching. The other onboard VGA port is a pass-through input for the graphics card output, and the system will seamlessly switch between the 2 outputs when the drivers are loaded.
Regarding the problems you were having with RAM, computers of that era frequently needed RAM sticks installed in pairs. It looked like you were only installing a single stick.
But you're forgetting, the NEC PC-9800 series is where Touhou Project originated (later being moved to MSWindows). I mean, you must have heard the 3rd Boss' theme from "Lotus Land Story"... (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-xNKyPkQ-_ug.html)
