gEDA-user: Re: Pointer to 3d CAD?

[Dave McGuire]

On Nov 1, 2006, at 11:16 PM, ldoolitt at recycle.lbl.gov wrote:
> I once personally diagnosed and replaced a blown diode in a PDP-5.
> When it blew, it made an accumulator bit stick on, and the machine
> became unusable.  That event caused the machine to be retired from
> the Caltech Cyclotron.  My friends and I found it abandoned many
> years later, in about 1978.  We fixed, refurbished, and played with
> it.  The process was very educational.

   Most excellent!  I bet that was a lot of fun.

> The PDP-5 was the predecessor to the PDP-8.  The big difference
> between the two was cycle time: 10us for the PDP-5 vs. 4us for
> the PDP-8, IIRC.  Each had 4K x 12 of core memory.  It's possible
> that machine is still kicking around Caltech; if you're interested
> I could make inquiries.

   I'm SO interested I can barely put it into words.  I am an avid  
minicomputer collector, with DEC as my specialty, and the PDP-5 is a  
very rare machine.  I've restored many PDP-8 and -11 systems, and I  
have quite a lot of VAXen (though not so old as to need restoration  
per se), and I pet them (and run them!) all regularly.

                  -Dave

-- 
Dave McGuire
Cape Coral, FL