@kenshirriff I think this is a 386SX chip. A little sibling chip with, I think, 16 bit external data path. Maximum supported RAM was 4MB and I bought such a PC with 1MB RAM as a 'smart purchase.' The PC ran MS-DOS, then Windows 3.1 It had a 40MB HD which, the seller said, would never fill up. With the Windows upgrade the RAM and HD had to be upgraded. The next PC after that was a PowerPC chipped Macintosh. That was an excellent computer in its day but hobbled by increasingly terrible OSs.