Click Here to visit our Sponsor
The History of Computing The Magazine Have Fun there ! Buy books and goodies
  Mistake ? You have mr info ? Click here !Add Info     Search     Click here use the advanced search engine
Browse console museumBrowse pong museum


Ready prompt T-shirts!

see details
ZX Spectrum T-shirts!

see details
Spiral program T-shirts!

see details
Atari joystick T-shirts!

see details
Battle Zone T-shirts!

see details
Vectrex ship T-shirts!

see details
C64 maze generator T-shirts!

see details
Competition Pro Joystick T-shirts!

see details
Moon Lander T-shirts!

see details
Atari ST bombs T-shirts!

see details
Pak Pak Monster T-shirts!

see details
BASIC code T-shirts!

see details
Vector ship T-shirts!

see details
Breakout T-shirts!

see details
Pixel adventure T-shirts!

see details
Shooting gallery T-shirts!

see details


Digital Equipment Corporation

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.

MANUFACTURER  Digital Equipment Corporation
TYPE  Professional Computer
YEAR  1965
KEYBOARD  ASR-33 Teletype
CPU  CPU was composed of 12 interlinked Register Boards
SPEED  1 MHz (0.5 MIPS)
RAM  4 K of 12 bit words
TEXT MODES  Depending of the terminal used
SIZE / WEIGHT  48 (W) x 55 (D) x 84 (H) cm. / 150 Kgs.
I/O PORTS  110 Baud serial interface
POWER SUPPLY  Built-in 780 Watts power supply unit
PERIPHERALS  Memory boards up to 32 Kwords
PRICE  $18.000 (Basic version)

Please buy a t-shirt to support us !
Ready prompt
ZX Spectrum
Spiral program
Atari joystick
Battle Zone
Vectrex ship
C64 maze generator
Moon Lander
Competition Pro Joystick
Atari ST bombs
Commodore 64 prompt
Pak Pak Monster
Pixel Deer
BASIC code
Shooting gallery
3D Cubes
Pixel adventure
Vector ship

Related Ebay auctions in real time - click to buy yours

Click here to go to the top of the page   
Contact us | members | about | donate old-systems | FAQ
OLD-COMPUTERS.COM is hosted by - NYI (New York Internet) -