DEC PDP-12, System Number 696

This December 1973 vintage PDP-12 was originally purchased by the Leesona Corporation in Warwick, RI. It was used to test a pneumatic computer (ALPS) that was an accessory to a weaving machine. It has some special I/O that was added by Leesona and is connected to the LINC Sense Lines. The in 2015 dollars this machine would cost $310,000.

The architecture of this system is a merge of a LINC (Laboratory Instrumentation Computer from MIT) and a PDP-8/I, so it has two modes for the processor, LINC and PDP-8/I. A single I/O instruction changes the instruction stream from one processor mode to the other. The LINC processor manages the digital and analog I/O, graphics, and the LINCtape. The PDP-8/I processor handles the disk, diskette, and other peripherals.

This system was built very late in the life of PDP-12s, so it has the Priority Interrupt and Data Multiplexer options pre-wired in the backplane. It also has an Omnibus expansion chassis so that it could have a large (2.5MB) disk drive.

The RX02 diskette drives and the RX8-E controller, and the paper tape reader/punch and the PC8E controller came from Brown & Sharpe.