So,on what sort of hardware was it that you wrote those Fortran programs? you wonder. I am glad you asked me that, it was an "ICL 4100 Computer system" and I have the technical information booklet (Second edition, October 1970) in front of me.

And what a machine it was. An ADD could be performed in a mere 5.6 microseconds. Integer division was a bit slower: 27.5 microseconds on the fastest 4130. Languages available included NEAT assembler, Algol, Cobol and, of course, Fortran (for real programmers only). Batch processing? Using T30C and DES one can assign periperals, load and run jobs and er...that's about it.

Let's check out the disc spec. Ah ha: a massive 4 Mb capacity, maximum transfer rate is 208 kbytes/sec.

There is also a mysterious "graphical display" which supports alight pen. I never got to use anything other than the card reader and theline printer.

Here are some photographs of this legendary machine, courtesy of Dave Gibson (click on the thumbnails to get the full-size pictures):
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