Photograph courtesy The ICT 1301 Resurrection Project
This machine had a 48-bit word and Core Store (in units of 400 words, to a maximum of 2,000), a Magnetic Drum for program overlays, Card Reader, Card Punch and Line Printer integral to the system and 7-track magnetic tape drives.
There were two 1301 systems where I started work as a trainee programmer (the Liverpool Victoria Friendly Society, then in Holborn, London), each had 5 magnetic tape units, one had 1200 words of store, the other 2000 words. Some jobs could only run on the larger machine. They had no operating system or assembler, binary programs being punched directly on cards.
At the time that I worked there, on the new ICL1904A, most live work was still running on the 1301s, we were writing replacement systems for the 1904A. There were still 2 programmers on maintenance work on the 1301s, unfortunately I can't remember their names, but can still recall what they looked like. These machines were rumoured to be the last working 1301s, and other machines being decommissioned were purchased for spare parts. One of these machines is now supplying parts to the ICT 1301 Resurrection Project. They also have the other machine.
In contrast, there were 3 or 4 applications programming teams of 7 people, plus a systems programming team of 4 people on the 1900. The systems team were responsible for George 3 maintenance and live systems maintenance, and consisted of senior programmers only. Note that the practice of putting junior programmers on maintenance was not followed at LVFS, you had to prove yourself before being 'promoted' to maintenance.