I got the final 486 processor that was made by Intel. It was a DX100, 100MHz and it was a small surface-mount IC on a daughter board with a 3.3V regulator. The daughter board was the same size as the older 486 processors and plugged in like one. No heatsink. It had double the amount of cache and a few other goodies like the 1st Pentium used.
It ran Win98 and high-speed internet just fine. Norton anti-virus scanning stopped it cold.