website/content/museum/digital-equipment-corporation-pdp-8.md

title, categories, types, origins, years, params

title	categories	types	origins	years	params
Digital Equipment Corporation PDP-8	Computers	Professional Computer	U.S.A.	1965	name image company company_name specs tabs forum_thread emulators links related oc_id source PDP-8 /media/museum/photos/dec_pdp8_system_1.jpg /companies/digital-equipment-corporation Digital Equipment Corporation label value NAME PDP-8 label value MANUFACTURER Digital Equipment Corporation label value TYPE Professional Computer label value ORIGIN U.S.A. label value YEAR 1965 label value END OF PRODUCTION 1980 label value BUILT IN LANGUAGE None label value KEYBOARD ASR-33 Teletype label value CPU CPU was composed of 12 interlinked Register Boards label value SPEED 1 MHz (0.5 MIPS) label value RAM 4 K of 12 bit words label value TEXT MODES Depending of the terminal used label value SIZE / WEIGHT 48 (W) x 55 (D) x 84 (H) cm. / 150 Kgs. label value I/O PORTS 110 Baud serial interface label value BUILT IN MEDIA None label value POWER SUPPLY Built-in 780 Watts power supply unit label value PERIPHERALS Memory boards up to 32 Kwords label value PRICE $18.000 (Basic version) emulators links 761 title url platform text SIMH http://simh.trailing-edge.com/ Windows Windows emulator for a lot of mini computers. Sources are available so you can compile them for your own platform. title url platform text PDP-8/E http://www.bernhard-baehr.de/pdp8e/pdp8e.html Apple emulator for the DEC PDP-8/E minicomputer running on the Apple Macintosh title url text Douglas W.Jones's DEC PDP8 Home Page http://www.cs.uiowa.edu/~jones/pdp8/ Wow, tons of doc and info here ! title url text More information about DEC PDP8 operating systems http://www.faqs.org/faqs/dec-faq/pdp8/section-10.html With PDP8 FAQ as well title url text PDP-8 Technology Before The Millennium http://www.pdp8.com/ PDP-8 Restoration Notes title url text Yet Another PDP-8 Web Site http://www.pdp8.net/ Lot of information and pictures /museum/digital-equipment-corporation-vt78 780 url date https://web.archive.org/web/20230608091007/http://www.old-computers.com/museum/computer.asp?c=780 2023-06-08

The PDP-8 was the first sucessful commercial minicomputer, produced by DEC in the 60s, the first real minicomputer, and the first computer costing less than $20,000.

By late 1973 to 77, the PDP-8 family was the best selling computer in the world. The basic version could sit on a desktop rather than requiring cumbersome racks well known at the time. This compact size caused it to become a popular system in scientific laboratories.

The machine had a now quite strange 12-bit word and four thousand 12-bit words of magnetic core memory. The first model was built without any Integrated circuit - thus no microprocessor - but with discrete transistors mounted on numerous small printed circuit boards called 'flip chips' that were inserted on two backplanes mounted vertically. Both table-top and rack-mount models were available, but adding additional memory required a rack.

CPU was composed of 12 interlinked Register Boards each operating on one bit slice of the 12 bit word and containing an Adder function together with all the major registers - MB, MA, AC, PC. Speed a little less than 1MHz.

The instructions set of the PDP-8 was very limited, only eight basic instructions encoded by the three left bits of each 12-bit word, and one register, the accumulator: However, the PDP-8 could be programmed to do almost anything. It just took longer (sometimes very longer!) to execute programs.

A 110 baud current loop teletype interface allowed an ASR 33 Teletype to be connected, serving as a console as well as a storage device by means of the built-in papertape puncher and reader.

There were numerous variations of the original model over the years, among them:
1966: PDP-8/S - minimum price but slow memory serial logic design
1968: PDP-8/I - first version with integrated circuits
1970: PDP-8/E - New bus structure design called Omnibus
1975: PDP-8/A - Allowed OEMs choice of memory type and quantity

All together, about 50,000 PDP-8 series computers were sold, as well as numerous clones made USA, Asia and East European countries.
In 2000 year, there were still a few PDP8's in operation, mainly in third-world countries.