Early memories – by Colin Jeffrey

In the early days of the 1970s, The LSI Dept did not have its own computer, so we had to run batch jobs on the STL Computing Dept’s IBM Mainframe. This involved laboriously writing pages & pages of coding, submitting them to ‘Angie’ to produce a stack of punched cards, then waiting till the next day collect your printout; only to find you had made a simple coding error rendering 40 pages of scrap paper (no recycling in those days). Later, we had to ‘borrow’ or buy time on John Winterbotham’s PDP8, downstairs in Z1.

The LSI Dept also decided to invest in one of the first Electronic Desktop Calculators; I think it cost around £1400 for a 4 FUNCTION machine with a 2 memory storage facility. We were really pleased, especially when we bought a 2nd one for around £200!

More early memories – from Chris Lincoln

When John Baxter learned that I had done programming at university, my first job when I joined the LSI Design Lab (the same day as Colin – so he nabbed the window desk & I had the corridor side desk) was to write a program in Basic on punched paper tape, which calculated PMOS transistor sizes to give the required drive and logic levels. (I could go on at length about ratio PMOS circuit design.)
The said punched paper tape was transported to John Winterbotham’s PDP8, which can’t have been far from D1 where we were, and set to work printing tables for hours on a teletype at 10CPS. Today I’m sure Health and Safety would have insisted on me wearing ear defenders while it was printing it was so noisy!

After that I wrote a logic simulator in Fortran on punched cards as Colin mentioned. That process did result in a lot of scrap punch cards – excellent for shopping lists – as well as scrap paper – but some useful results too. After that when technology had moved on the VLSI group as it was by then declared UDI from IBM and bought a 32 bit Prime super mini then Apollo workstations then Sun UNIX workstations.