Method for distinguishing between a 286-type central processing unit and a 386-type central processing unit

摘要

A method is disclosed for distinguishing between the Intel 80386 and 80286 CPUs. Bits 12, 13, and 14 of the 386 flags word in the real mode are always zero in the 286 architecture and cannot be set, but can be set to a one on the 386. The method includes the steps of attempting to set any of those bits and examining the results. A source code listing is attached.