The PDP-8 was the first computer to be mass produced at an affordable cost, and it has been described as the Model-T of the computer industry. At a time when other computers sold for more than US$ 1 Million, the PDP-8 "minicomputer" sold for US$ 18,500. The term minicomputer is understood to have been first used in a sales report from the DEC head in Britain: "Here is latest minicomputer activity in the land of miniskirts, as I drive around in my Mini Minor" The term quickly became part of computer jargon.

This particular PDP-8 has numerous other pieces of prototype equipment incorporated in the rack frame that houses the main frame. Much of this was developed in various experimental and student projects at the Basser Department of Computer Science.

This object is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.

Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Antikythera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.

The PDP-8 is a general purpose, stored program computer. This particular unit is mounted in a rack with removable Perspex sides and front. There are two swinging frames, containing discrete transistors and components on circuit boards. At the top of the rack there is a multiplier designed by an honours student, using standard modules made in the University Department. The actual computer is mounted below the multiplier. Next, there is the operating panel with a number of switches, the power supply, additional core memory and a disk drive. Transistors and other discrete components are mounted on a multitude of circuit boards.

The PDP-8 is a 12-bit single accumulator machine. The ferrite core memory is 4k (4096) words with an additional 4k expansion memory. The word length is 12 bits, and it has 8 basic instructions, executing them in 1.2 to 4 microseconds. Access time is 20 milliseconds. The arithmetic uses two's complement.

Made: 1965 - 1990

Digital Equipment Corporation, Data Processor, PDP-8

2010/1/109

1965 - 1990

1835 mm

575 mm

690 mm