The PDP-11/45 had split I/D capabilities. It was not all that much later than the 11/20 (2 years according to Wikipedia anyway).
On 7/13/2015 2:16 PM, Rich Alderson wrote: > From: Kip Koon > Sent: Sunday, July 12, 2015 10:52 PM > >> I would be most interested in finding out more about this effort. Do you >> have >> ongoing pictures documenting this effort? I'd love to have a PDP 8, 11, 12 >> someday, but I don't have the space for something like that much less the >> cost >> involved so I'll have to be satisfied with emulators on my PC or eventually >> building one or more of these systems with current technology like the >> SBC6120 >> if memory serves. Are there other possible alternatives? I used a PDP-8/E >> in >> high school and college and have been quite interested in the high capability >> PDPs like the PDP-11 Series for starters. I didn't know there were PDP 12 >> Series computers. Are there other PDP series computers as well? > > Don't confuse higher numbers with higher capabilities, or even as being > related > to each other. DEC created computers with 9 different architectures before > the > 32-bit VAX was even dreamed of. > > The list of Programmed Data Processors goes like this: > > PDP-1 18-bit word, 12-bit address > PDP-2 24-bit word, paper design only > PDP-3 36-bit word, paper design only > PDP-4 18-bit word, 13-bit address > PDP-5 12-bit word > PDP-6 36-bit word, mainframe unrelated to PDP-3 > PDP-7 18-bit word, PDP-4 successor > PDP-8 12-bit word, PDP-5 successor > PDP-9 18-bit word, PDP-7 successor > PDP-10 36-bit word, PDP-6 successor mainframe > PDP-11 16-bit word, 16-bit address[2] > PDP-12 12-bit word, PDP-8/i + LINC hybrid > PDP-14 control processor for customer-built special purpose equipment > PDP-15 18-bit word, PDP-9 successor > PDP-16 Register-Transfer Module hard-wired processor, PDP-14 > competitor[3] > > There were later variants of some of these: > > PDP-7A > PDP-8/s, PDP-8/i & /l, PDP-8/e & /f & /m, PDP-8/A > PDP-9/L > PDP-15/76 > > After 1971, they stopped naming things "PDP-n", with the exception of models > of > the PDP-11 (which eventually consisted of more than 20 models designated > PDP-11/nn), but even there the Pro-3x0 desktop systems were called something > else. Later models were microprocessor-based. > > The later PDP-10 models were designated DECsystem-10 and DECSYSTEM-20. > > The later PDP-8 models were the DECmate, DECmate II, and DECmate III (word > processing desktop systems) and the VT-78, all based on Intersil or Harris > microprocessors which were roughly the PDP-8/e in silicon. > > "high capability PDPs" = PDP-10 & follow-ons. PDP-11? Pfeh. > > Rich > > [1] 1 built by a customer, reputed to be an NSA front company. > > [2] With memory management, 18 or 22, in 16-bit segments. Late models could > use separate instruction and data segments, for a total of 128KB in use at > one time. > > [3] Different model lines had separate sales teams, and competed against each > other across the company for sales. > > > Rich Alderson > Vintage Computing Sr. Systems Engineer > Living Computer Museum > 2245 1st Avenue S > Seattle, WA 98134 > > mailto:ri...@livingcomputermuseum.org > > http://www.LivingComputerMuseum.org/ >
