PDP-1

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PDP-1, (Programmed Data Processor-1) the first computer in DEC's Programmed Data Processor series, first launched in 1960, forerunner of the PDP-8 and PDP-11 minicomputers, and the World's first commercial interactive computer used for process control, scientific research, and graphics programming, as well as to pioneer timesharing systems.

Based on the TX-0 and TX-2 computers he had designed at MIT's Lincoln Laboratory, Ben Gurley constructed the PDP-11 in under three–and–a–half months. The PDP-1 had 4K 18-bit words as standard main memory, upgradable to 64K words, and an internal instruction execution rate of 100,000 to 200,000 per second. Signed numbers were represented in ones' complement.

=Hardware= The processor consists of discrete germanium transistor logic in form of System Building Block modules, inserting 25 of them into a 5-1/4 inch section of a custom 19-inch rack. System Building Block 1103 - hex-inverter card

=Assembly= In the early 60s, Edward Fredkin, while affiliated with BBN, wrote the first PDP-1 assembler called FRAP (Fredkin’s Assembly Program). Ed Fredkin working on PDP-1 (1960 ca.)

=PDP-1 Chess= As told by Alan Kotok at the PDP-1 Celebration Event Lecture, May 15, 2006, PDP-1 Chess, a apparently strong new chess program developed at BBN or elsewhere, was a hoax. Kotok, at that time in the early 60s student at MIT and PDP-1 programmer, was member of the Tech Model Railroad Club as well as member of the chess group around John McCarthy, and already co-author of Kotok-McCarthy for the IBM 7090. He and some of his colleagues had established a network, a TTY connection between the PDP-1 and the TX 0 in an adjoining room, where some of the better MIT chess players "simulated" PDP-1 Chess with a chess board at the TTY console, playing a game versus some testers with McCarthy involved. The "cheat" was finally noticed, when later during the game both board positions somehow became out of sync.

=Spacewar!= In 1961/62, Steve Russell developed [https://en.wikipedia.org/wiki/Spacewar! Spacewar!], one of the first interactive video games, after Alan Kotok obtained some sine and cosine routines from DEC.

=See also=
 * PDP-6
 * PDP-8
 * PDP-10
 * PDP-11

=External Links=
 * PDP-1 from Wikipedia
 * Restoring the DEC PDP-1 Computer Exhibit at The Computer History Museum
 * DEC PDP-1 Collection from The Computer History Museum
 * Digital Computing timeline 1960 - PDP-11
 * The Mouse That Roared: PDP-1 Celebration Event Lecture, May 15, 2006 (1:53:44) Mountain View, CA, USA: © 2006, The Computer History Museum. Panel discussion including Alan Kotok (53:50) and John McCarthy (1:27:20), moderated by Edward Fredkin from 17:40, YouTube Video

=References=

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