On Tue, 09 Oct 2007 22:13:07 -0700, ChairmanOfTheBored
wrote:

On Tue, 09 Oct 2007 20:52:11 -0700, John Larkin
wrote:

I have two 9100's, both dead, and HP refuses to release the
schematics, after over 30 years!


Well trace back through it, and draft one up.

Show us how it's done!

That would be a monstrous amount of work, and most of the logic is in
little epoxy-dipped sip-type boards, like the things you used to see
in old TV sets.

The 9100 used core memory to store the program; if it was running a
program, you could shut it off and turn it back on, and it would keep
going. It had three different roms: diode matrix, resistor matrix, and
a multilayer pcb that used magnetic coupling between layers.

The HP archivist has all the docs, but won't let me see them. But they
spent over a million bucks to buy "the garage."

John