From: Mark Wickens Sent: Thursday, December 04, 2014 12:47 AM You know, there never was (or only for a very short time) such a thing as "the PDP". DEC produced systems with 5 different architectures (or 4.5, if you lump the two 18-bit architectures together; I usually do) under the rubric "PDP-<small integer>": The PDP-1, the PDP-4/7/9/15, the PDP-5/8 family, the PDP-6/10 family, and the PDP-11 family. I would argue that only the original PDP-1 could rightly be called "the PDP", but even then, DEC had designed the 24-bit PDP-2 and the 36-bit PDP-3 which they did not build themselves, for a total of 7 architectures designated "PDP". Back when I was doing sales support for XKL, a lovely lady who did consulting in the oil industry advised me that we should be selling the Toad-1 in that market "because there are PDPs *everywhere* in the fields!" (Steps off soap box, walks away from Hyde Park.) (Hi, Mark! ;-) Rich Rich Alderson Vintage Computing Sr. Systems Engineer Living Computer Museum 2245 1st Avenue S Seattle, WA 98134 mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/