That's one of the things with PC's... they're all software-standard, but hardware versatile. For 486's, there's the Pentium Overdrives that some boards were equipped with (but Intel cut off the overdrives early), then there's also about 50 differnet chips that actually plug into the ZIF Socket, the fastest being the Evergreen one, which is based on a AMD K5 133, and has equivelent performance to that of a Pentium 102MHz. For the Zeineth PCs that the government bought in the 80's, the CPU was on a daughterboard, so that you could upgrade that to a 386, but God help you try to find one of those. -----Original Message----- From: Max Eskin <maxeskin(a)hotmail.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Tuesday, March 03, 1998 2:13 AM Subject: 486 upgrade boards