Sometime in 1987, or thereabouts, I was working with various Intel processors. For some reason I needed to know which type of CPU some code was running on, so I wrote a routine that would determine whether the processor was an 8086, 80186, 80286, or 80386 and, if a 286 or 386, whether it was running in real or protected mode. I wrote an article about it which was first printed in PC Tech Journal, November 1987, on page 51. Somewhere I still have a copy of that issue. Somewhere. The article was then anthologized in Dr. Dobb's Toolbook of 80286/80306 programming on pages 75 to 78.
The text of the article and the source code is below the fold. I wish I had my original work to show how it was edited for publication.
