PDP-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].
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 * [[image:PDP-1.jpg link="http://en.wikipedia.org/wiki/File:PDP-1.jpg"]] ||~ || **PDP-1**, (Programmed Data Processor-1)

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]. toc =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].
 * PDP-1, [|CRT], [|TTY] and processor rack ||~ ||^ ||
 * PDP-1, [|CRT], [|TTY] and processor rack ||~ ||^ ||
 * [[image:Dec_SYSTEM_BUILDING_BLOCKS_1103.jpg width="592" link="http://en.wikipedia.org/wiki/File:Dec_SYSTEM_BUILDING_BLOCKS_1103.jpg"]] ||
 * 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 [|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= > media type="custom" key="24224856"
 * [|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= =What links here?= include component="backlinks" page="PDP-1" limit="60"
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