The main improvements over it were in the size of the primary and secondary storage, a faster multiplier, and additional instructions.

Secondary storage was provided in the form of a 512-page magnetic drum, storing two pages per track, with about 30 milliseconds revolution time.

[1] Several instructions were included to copy a word of memory from one of the Williams tubes to a paper tape machine, or read them back in.

As a result, the characters representing the values from 0–31 (five-bit numbers) looked entirely random, specifically /E@A:SIU½DRJNFCKTZLWHYPQOBG"MXV£.

Ferranti had high hopes for further sales, and were encouraged by an order placed by the Atomic Energy Research Establishment for delivery in autumn 1952.

The company ultimately sold it to the University of Toronto,[9] who had been building their own machine, but saw the chance to buy the complete Mark 1 for even less.

[10] FERUT was extensively used in business, engineering, and academia, among other duties, carrying out calculations as part of the construction of the St. Lawrence Seaway.

[14] Included in the Ferranti Mark 1's instruction set was a hoot command, which enabled the machine to give auditory feedback to its operators.

The sound generated could be altered in pitch, a feature which was exploited when the Mark 1 made the earliest known recording of computer-generated music, playing a medley which included "God Save the King", "Baa Baa Black Sheep", and "In the Mood".

[15] The recording was made by the BBC towards the end of 1951, with the programming being done by Christopher Strachey, a mathematics teacher at Harrow and a friend of Alan Turing.