Lindsay.Marshall@newcastle.ac.uk (Lindsay F. Marshall) (01/18/90)
Seeing we're talking about PDP's. Anyone remember the PDP-16? This was'nt an actual machine but was a collection of asynchronous cards that could be hooked together to build your own systems. We used to use them for hardware experiments when I was a student and they were very susceptible to static 'cos I remember being able to start up one system that I built simply by olling my chair across the floor. Also how about any Interdata 70 fans out there? I seem to recollect that the teletype port used the *same* buffer/register for both input and output making I/O a little hard to get right. I also noticed a mention of the Burroughs B1700 in the flashing lights discussion. What a really great machine that was. Way ahead of its time. Ours had very slow, unreliable discs and a *very* fast card reader and printer on it. The trouble was that we could never drive the card reader at faster than about 5 or 6 cards a minute as parts of the microcode that drove system were always being swapped in and out. It turned out, that there huge chunks of the I/O system devoted to driving all kinds of weird things like cheque sorters and when this was all choppped out things went a lot better. You wrote the microcode in an assembler that was modelled on COBOL..... but all the same one of my all time favourite machines right up there with the PDP-8, PDP-15 and PDP-11/45. Lindsay -- MAIL : Lindsay.Marshall@newcastle.ac.uk (UUCP: s/\(.*\)/...!ukc!\1/) POST : Computing Laboratory, The University, Newcastle upon Tyne, UK NE1 7RU VOICE: +44-91-222-8267 FAX: +44-91-222-8232