I have never seen a VLB motherboard that supports 486dx4-100mhz CPU.
What motherboard models support this ?
You've never come across a VLB board for 3.3V? That's really unlucky 🙁
I currently have 3 VLB boards; an A-Trend OPTi-895 486 Green, a Legend QDI V4P895P3 and a (probably) OEM board, manufactured by Iston Corp. called S486G. They all support DX4.
It seems to me, that most of the board with a ZIF socket, also come with the voltage regulator for 3.3V CPUs. It's a very distinct looking three legged fellow with a screw-bracket on the top. Sometimes they have a heatsink mounted to them, but not always.
WinXP : PIII 1.4GHz, 512MB RAM, 73GB SCSI HDD, Matrox Parhelia, SB Audigy 2.
Win98se : K6-3+ 500MHz, 256MB RAM, 80GB HDD, Matrox Millennium G400 MAX, Voodoo 2, Waveforce 192XG.
DOS6.22 : Intel DX4, 64MB RAM, 1.6GB HDD, ELSA Winner 1000PRO, GUS 1MB, SB16.