PDP-11/34 Progress Report

From: Jeffrey Sharp <jss_at_subatomix.com>
Date: Sun Mar 9 04:59:00 2003

I've made some progress with my PDP-11/34. Since last week's PSU
corn-fusion, I pulled all the cards, air-dusted them, air-dusted and
inspected the backplanes, took an inventory of jumper and DIP switch
settings, put a minimal CPU+mem+console card set in, connected the
backplanes to the PSU, and turned on the machine. It was a little more
complicated than that, but I've got what seems to be a working 11/34 in my
living room.

Learned: As I had mentioned previously, my M9312 had a strange start address
dialed into its DIP switches by one of the previous owners. That has to be a
mistake. When the machine boots, it immediately halts. If I manually start
the processor at the correct address for the console emulator, I get a
steady run light. I do not have a console terminal attached yet.

Learned: A previous owner had a rocker-style DIP switch block on the console
DL11-W set backwards (i.e. one's complement of the correct setting). The
DL11-W was being configured with the wrong interrupt vector.

Learned: If you plug in a G727A bus grant card backwards, the processor will
not halt. :-)

To do: My only existing cable that plugs into a DL11-W is for 20mA current
loop. I have a current loop VT52 that I haven't yet tested. I'll see if I
can do that tomorrow. After all, it would be nice to know if the register
printout is actually occurring.

It's so late it's early; therefore, I should go to bed. Tomorrow I'll run
some test programs!

-- 
Jeffrey Sharp
Received on Sun Mar 09 2003 - 04:59:00 GMT

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