Comments on: PDP-9 console arrives http://pdp9.co.uk/2009/07/16/pdp-9-console-arrives/ Charting the history and preservation of DEC PDP-9 computers Sat, 16 Jan 2010 18:41:30 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: CRC http://pdp9.co.uk/2009/07/16/pdp-9-console-arrives/#comment-43 CRC Sat, 16 Jan 2010 18:41:30 +0000 http://pdp9.co.uk/?p=7#comment-43 The PDP-9 was essentially the first computer at which I learned what computers were about. On it I learned Fortran II and IV as well as assembly. In addition, I invented the operating system in order to use the DEC Tapes - that was until I found a DEC Tape with the operating system already present. At the time we received the beast (1972 - surplus) I was already banging on a DG Nova 1200. The '9 had 8k words of memory, paper tape reader and punch, two DEC Tapes, and a X-Y CRT. The Nova ran our nuclear data analyzer and generated paper tapes off a clunk-clunk which then were used to punch cards which fed the local CDC 6400 for analysis. I programmed the '9 to read in the tapes and used the CRT and light pen to do the background fitting saving literally a month of time. The program took 5 chains to execute. On damp days the beast would fail and we would have to stuff punch cards into the control memory to keep it up. With all the work studiying the designs to keep the thing going, the asynchronous design totally screwed my interface designs for years... In the '80s one of my customers had one in a back room and, without thinking, I keyed in the boot sequence and brought the thing up - something I don't think I could do today. Good luck with your project!! The PDP-9 was essentially the first computer at which I learned what computers were about. On it I learned Fortran II and IV as well as assembly. In addition, I invented the operating system in order to use the DEC Tapes – that was until I found a DEC Tape with the operating system already present.

At the time we received the beast (1972 – surplus) I was already banging on a DG Nova 1200. The ‘9 had 8k words of memory, paper tape reader and punch, two DEC Tapes, and a X-Y CRT.

The Nova ran our nuclear data analyzer and generated paper tapes off a clunk-clunk which then were used to punch cards which fed the local CDC 6400 for analysis. I programmed the ‘9 to read in the tapes and used the CRT and light pen to do the background fitting saving literally a month of time. The program took 5 chains to execute.

On damp days the beast would fail and we would have to stuff punch cards into the control memory to keep it up. With all the work studiying the designs to keep the thing going, the asynchronous design totally screwed my interface designs for years…

In the ’80s one of my customers had one in a back room and, without thinking, I keyed in the boot sequence and brought the thing up – something I don’t think I could do today.

Good luck with your project!!

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