PDP-9 lives again....

From: The Wanderer <quapla_at_xs4all.nl>
Date: Fri Aug 30 14:37:00 2002


Now the next question: when may we see some pictures (via a web link)?


Hans B Pufal wrote:
> Some 20 odd years after it was decommisioned we finally got our PDP-9 to
> boot software off an old DECTape. Advanced Software System version 5A
> came up today for the first time on our restored -9.
> This after a long and frustrating summer when we spent over 100 man
> hours chasing a processor fault which resulted in the execution of the
> saved PC value after an interrupt (instead of the word after the saved
> PC value). Turned out to be a misaligned delay circuit which caused a
> reset signal to arrive late and provoke all sorts of havoc in the
> processor while nicely reseting all the tell-tales.
> Seems like the memory and processor hardware is quite stable now. We
> have two DECtape units attached with two more units availabe to be
> attached. Further debug on the DECtapes and learning the software will
> be followed by attachemnt of TU20 mag tape units.
> If anyone knows of an available (and cheap) large X-Y plotting scope
> preferably somewhere in europe we would be very interested in hearing
> from you. We have a graphics controller but no large screen. With the
> screen, the DECtapes and the TU20's this is going to be one impressive
> system.
> We also used the -9 for the first time today to try and recover an image
> from an old Elliott 903 paper tape I was given in the UK recently. Due
> to operator error that attempt failed but I fully expect to be able to
> get a tape image this weekend.
> -- hbp

Received on Fri Aug 30 2002 - 14:37:00 BST

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