Don't know about the HP cord! The HP-200C, etc., that I have use the same power cord as "modern" computers. Glen, K9STH Website: http://k9sth.com --- On Mon, 3/28/11, Jack <wa9nqw at nconnect.net> wrote: Looks like this cord may be close to fitting the elusive 3 prong "old style" HP instrument power cord as well.