The Manchester Mark I and atlas

Abstract

In 30 years of computer design at Manchester University two systems stand out: the Mark I (developed over the period 1946-49) and the Atlas (1956-62). This paper places each computer in its historical context and then describes the architecture and system software in present-day terminology. Several design concepts such as address-generation and store management have evolved in the progression from Mark I to Atlas. The wider impact of Manchester innovations in these and other areas is discussed, and the contemporary performance of the Mark I and Atlas is evaluated.

DNA synthesis for true random number generation

“…The increasing necessity of being able to generate large quantities of random numbers for societal needs is made obvious when viewing the technological developments thereafter: About half a century later, solving problems with probabilistic procedures demanded a volume of random numbers much greater than that a dice could produce efficiently 2 . Thus began a series of technological breakthroughs including the first integration of a hardware random number generator (RNG) into a real computer, the Manchester Mark I, by using electrical noise 3 . Shifting from algorithm to interactions, the modern world required network security services, and thus introduced encryption and decryption schemes for exchanging information securely, requiring high-quality random numbers (generated faster while being less prone to attacks) 4 , 5 .…”

Tom Kilburn

“…However, in January 1959, Ferranti, with £300,000 in backing from the National Research Development Corporation (NRDC), decided to participate in the project, now renamed Atlas. 11 Among the innovations introduced in the Atlas was a scheme that let programmers treat drum stores as if they were core storage. An innovative program called the supervisor managed drum transfers.…”

Computation and its limits

“…The Manchester Mk I on which Turing worked as a programmer was the first programmable general purpose electronic computer. It had about 4000 valves and used 25 Kilowatt [53,54,55]. It operated at a clock speed of 85KHz so that to perform one logical operation with a triode was using about 6 × 10 −5 Joules, the calculations on page 70 indicate that the gates on the K10 use about 2.6 × 10 −15 Joules per logic operation.…”