PC Hardware A Beginner’s Guide

(^58) PC Hardware: A Beginner’s Guide
Intel 80386, 80386DX, and 80386SX
Intel released the 16MHz 80386, commonly called the 386, in 1985. The 386 microprocessor
was a full 32-bit processor packaged in a 132-pin PGA package. The 386 had 275,000 tran-
sistors and had the clock speed to support over 5 MIPS.
While it had a 32-bit mode, which meant it was able to move data in bytes, 16-bit words,
or 32-bit double words (ordwords). Two features provided by the 386 were improved vir-
tual memory capabilities that allowed large amounts of memory to be temporarily stored
on the hard disk and instruction pipelining, a process that preloads and pre-evaluates com-
plex instructions, which results in faster processing speeds. The Intel 386 had versions with
clock speeds ranging from 16MHz to 33MHz. However, other manufacturers, specifically
AMD and Cyrix, had competing processor versions with speeds up to 40MHz.
Figure 3-11. The Intel 8088 microprocessor. Photo courtesy of Intel Corporation