identify CPU UMC

UMC

Pre 80486 ?? ?? ?? ?? 80486 4-1-X U5D 486DX, 25..40MHz, 0.6µm, 1994 8KB L1   4-2-3 U5S 486SX, 25..40MHz, 0.6µm, 1994     U5SF-Super33 U5S in QFP, 33MHz     U5SLV-Super25/33 U5S, 3.3V, 0.6µm, 1994     U5FLV-Super25/33 U5SLV in QFP     4-3-X U486DX2     4-5-X U486SX2

U5x violates intel patents, therefore not sold in USA

UMC U5SDLV
D - 486DX compatible PGA
none - 486SX compatible PGA
F - 486SX compatible LQFP

LV - 3.3V (some 3.3V parts are sold as 3.0V) none - 5.0V