That is extremely cool! I agree that is too bad that the whole lab
cannot be kept intact. What is to become of the van de graph generator?
Is that being taken apart as well?
I hope that someone will be able to save and maintain the pdp7 in a
running or runnable state. I wish that I had the time, money, and
space to do it myself...
At 03:29 AM 6/15/02 EDT, you wrote:
Finally was able to get a look at the PDP 7. I think it
qualifies as the
of the week, or year, for me.
I have corresponded with those most interested in it. If interested please
contact me offlist at whoagiii(a)aol.com.
Here is the report;
I saw the PDP 7. It is a delight. It is too bad the entire Lab could not be
saved as a museum. The computer was installed in 1965 to run a 5 MEV Van de
Graff Generator which had been installed in 1964. There is still one
experiment running in the lab so it is not being shut down yet.
The PDP 7 was replaced in 1992 with a RIDGE 32. The RIDGE 32 was replaced in
1999 with a SUN IPX which runs the Van de Graf via a GPIB connection.
However the PDP7 was not removed or even disconnected. Harlan fired it up,
tried to load a program off a disk drive, by first running a punch tape.
Finally got the tape loaded and you could see action in the homemade disk
drive controller, but nada.
He was able to key in a simple program via the front switches that ran.
Classic blinkin lights, wow!
Evidently it is a Germanium transistor computer. Germanium, not being as
stable as silicon, needs more love, care and attention to keep it running.
There are two cabinets of boards and parts including extra core. It
originally came with 4K of Core but they upgraded it with 4K more for a
It has a 555 DECTAPE drive, a paper tape reader and desk in the central
cabinet. It is 6 cabinets wide, however these are a narrow double door
cabinet so the entire computer doesn't seem massive. It is cute! The paper
tape punch is in the cabinet to the far left with 4K of core underneath.
Second to the left is the other 4K and the power supplies for the memory.
third from the left is the console, desk and paper tape
reader. IIRC there
are three more cabinets to the left, the last two sparsely populated. All
cards are singles, early flip chip style.
It originally came with a KSR 33 Teletype which is long gone. They used an
ADM terminal in a roll around rack. Above the terminal is a HP1300 display.
At the top are two DEC floppy drives with the Lab's own homemade disk
controller. All this should be visible in the pictures.
There is an entire file cabinet drawer of docs and paper tapes. Several
of boards and components, as Harlan said, a complete
set of spares. he also
indicated they were familiar with board level repairs and that is what it
took to keep it running. They inherited lots of tapes from a PDP10 at one
time, because they could use the same ones. There are several cabinets of
It is a classic museum piece.