Intel 80386 microprocessor family

25 MHz

16 MHz
132-pin ceramic PGA

16 MHz
132-pin ceramic PGA

168-pin ceramic PGA

Embedded 386 processors from EX series were produced with at least three different steppings: A0, B1, and C1. The stepping can be easily determined visually from processor markings. The FPO line (the line below the part number) contains an extra character at the end, that identifies the stepping code: "A", "B" and "C" stand for A-stepping, "D" stands for B-stepping and "E" stands for C-stepping. Intel produced 4 different variations of 80386EX CPUs with different electrical characteristics, and these can identified from the two-letter code, located below the FPO line. "SA" corresponds to "EXSA", "TA" - "EXTB", "TB" - "EXTB" and "TC" corresponds to "EXTC".

33 MHz

Stamped "Sample"

25 MHz

25 MHz

25 MHz

386 upgrade for 286 computers

33(?) MHz
132-pin ceramic PGA