ACD Atlas Computing Division Prime Computer Systems

Jump To Main Content

Jump Over Banner

Home

Jump Over Left Menu

Prime Systems and the ICF

An Overview of Prime's system developments is:

1972: Prime 200
The first Prime system, similar to the DDP 516 but a 32-bit machine with paging
1973: Prime 100 and Prime 300
The Prime 100 was a stripped down version of the Prime 200 (no memory parity or floating point). The Prime 300 was the current system at the time ICF was being launched.
1976: Prime 400
By 1977, the Prime 300 was being replaced by the Prime 400. The Prime 300 was withdrawn in 1979. The ICF Prime 400 arrived in December 1977.
1979: Prime 450, 550, 650 ,750
The Prime 550 was an upgrade in performance over the Prime 400 while the Prime 750 was a major upgrade which was very competitive with a similarly priced DEC VAX System. PRIMENET and the local area network software RINGNET were announced. Four Prime 550 systems were installed in 1979 and 1980. Prime 750 systems were installed at RAL and UMIST.
1980: Prime 150 and 250
1981: Prime 850
Prime also marketed MEDUSA CAD Software
1982: Prime 2250
1984: Prime 2550, 9650, 9750
1985: Prime 9955, 9655, 2655
A Prime 9955 was installed at UMIST and a Prime 9655 at Nottingham in 1985
1986: Prime 2350, 2450, 9755, and 9955-II
1987: Prime 2455, 2755, 6350, and 6550

A summary of the Prime systems installed by ICF is:

Location Initial Machine Intermediate Machine(s) Final Machine
Date Type Date Type
RAL (Services) 1977 P400 2 × P400; 2 × P750 1986 P9955
RAL (Dev) 1977 P300 P400; P550/1 1986 P9655
Sussex 1979 P550/1 - - -
City 1980 P550/1 - 1986 P750
Surrey 1980 P550/1 - 1986 P550/2
UCL 1980 P550/1 - 1986 P750
UMIST 1980 P750 P9950 1985 P9955/1
Warwick 1980 P550/1 P550/2 1986 P750
East Anglia 1979 P400 - 1986 P750
Nottingham 1977 P400 - 1985 P9655

The original Prime 400 ran at 0.5 MIPS, had a main store of 192 Kbytes and 160 Mbytes of disc storage. Typical configurations for the main systems used by ICF were:

P550 P750 P9955
MIPS 0.7 1.0 4.0
Memory (Mbytes) 1.0 2.0 - 4.0 8.0 - 12.0
Disc Space (Mbytes) 500 1200 2700
Magnetic Tape Unit
(9 track)
1 1 1
Printers 1 1 1
Plotters 1 1 1

Prime 400

Prime 400
Large View

Prime 550

Prime 550
Large View

Prime 750

Prime 750
Large View