PDP-2

"The PDP-2 designation was saved for a possible 24-bit machine, but none was ever built." - from [Gordon Bell's book Computer Engineering - A DEC View of Hardware Systems Design

"In the late 60's & early 70's I worked for a company (Medidata, later Searle Medidata) which started life as a not-for-profit spin-off from Lincoln Lab. (as I have heard), called American Science Institute. The chief engineer, Ed Rawson was a friend of Dec's Olsen and he managed to get hold of the modules used for the prototype PDP-2 which never reached the market. ASI used them to build their own machine (designed, I believe, by Chuck Corderman) which they called "Casino" and was sometimes jocularly referred to as a PDP-2 1/2. Casino was noteworthy for having, very early in trhe game, graphics capabilities. It also had some special terminals which had labels that cannot be repeated on this (family) newsgroup." - February 3, 1997 alt.sys.pdp10 message from Max ben-Aaron.