For other news, I've been playing with a Cirrus Logic GD5428 card in the hopes of having a more compatible card for use with alternative operating systems since the VLB Trio64V+ is so weirdly rare (likely not meant to exist explicitly) that drivers only exist for Windows 3.x and 95, drying up in January of 1997. The generic S3 driver for Windows NT corrupts the display, and XFree86 on Debian 2.1-2.2 has absolutely no clue what it is, locking up the entire machine when trying to invoke either the S3 display server or the generic SVGA one, though that bit may well be because modelines are a huge barrier to X use on early Linux.
First card I got was a dud. It happens, I really ought to have known better since "untested" on eBay means "definitely tested, definitely doesn't work". I thought I'd be able to coax it into functioning with a VBIOS flash, as I've seen that work before, but no. Didn't spend a lot on it though, so I'm not too broken up. I can rob it of its video memory at my leisure.
Second card acts the same... but this one is tested and working...? On a whim I try it with a real 486 in the upgrade socket, and it boots right up after complaining about the CMOS checksum being invalid... but the plot thickens, because after removing the real 486, now the 5428 works with the regular 486BL mounted on the board. Talk about bizarre -- apparently the CMOS does store some amount of information about the VGA card, meanwhile I just figured it looked for a ROM at C8000 and just handed over the reins. I really did figure as far as the BIOS was concerned, a VGA card is a VGA card is a VGA card, and I guess swapping CPU types jolts the CMOS into just discarding everything and re-detecting everything anyway.
The first card still doesn't give a display, but it no longer gives a beep code, either. Weird.
The 5428 is a little bit more of a pain to use than the Trio in some ways -- for example it doesn't autodetect the display specs through DDC, instead there's a DOS tool you run to flip some bits in the card's registers in order to get more than 60Hz at 640x480 and 56Hz at 800x600. Once that bit of fiddling is done with though, it's fine -- I have my video mode set to 800x600 in 256 colors at 72Hz. Thank God for multisync CRTs that can handle these oddball refresh rates -- I have a feeling an LCD would just look at that and go "lol you're on your own."
Also there doesn't seem to be a card or chipset-specific VESA 2.0 VBIOS extension TSR available for it. I figured as much since the 5428 is, IIRC, a 1993 part made well into 1994. UniVBE 6.7, the free release, doesn't recognize the chip despite explicitly mentioning it in its readme. Running real SciTech Display Doctor v6.53 fixes me right up though. That said, the linear framebuffer doesn't get enabled apparently because on systems with more than 14MB of system memory enabling the LFB can cause lockups with this chipset. An interesting quirk. SimCity2000 and WarCraft II run perfect, though.
Overall it's a bit slower than the Trio, but it actually functions better, believe it or not -- no corruption in screensavers, no weird corruption issues with the Neverhood, it's almost like this was a card intended for this class of machine, go figure.
The S3 is nice as a display piece, being so comparatively rare.