11/45 progress

From: Tom Uban <uban_at_ubanproductions.com>
Date: Sun Feb 13 21:56:21 2005

>Ok, that's what I wasn't sure of, if the ripple & voltages could be tested
>without any cards at all. I'm aware they need to be rechecked under the
>load of the cards, but wanted to make sure things were at least reasonable
>before subjecting my only cpu cards to the power.

I'm sure that it won't hurt the supplies to run them unloaded, although they
may sing at a slightly different pitch.

>I thought they were, but I was trying to ascertain exactly where the pins
>were documented. Being new at a unibus restoration, I didn't want to guess
>at anything.

The peripherals handbook has the unibus pinout in the back. Then you just need
to check the correct slots in the backplane, typically the termination slots
in the CPU backplane and the first and last slots in unibus backplanes.

I'm sure there are numerous places, but here is the first one that showed
up on a google search of unibus pinout:


The unibus only has +5/Gnd, so you will have to go to lookup the other
supply locations which are CPU backplane specific. As I indicated, the
heavy wires are for power and you should be able to locate +5, +8, +15,
and -15.

You can look on bitsavers.org for the 11/45 print set, or you can grab
a copy of appropriate section of the manual from my site. I think I got
this scan from either http://bitsavers.org/pdf, or http://vt100.net/manx/.


On the sheet labeled 11/45 BACK PANEL PC BOARD is a table with the power
info you need for the CPU. One or two of the voltages may not be present
if you don't have the MOS/Bipolar memory and related power supplies, but
you should minimally find the four supplies listed above.

Received on Sun Feb 13 2005 - 21:56:21 GMT

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