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RCS Online Library

We have scanned a large set of historically interesting manuals & documents over at the museum, and posted them online:

https://www.rcsri.org/library/

We're not trying to post a complete reference section, but a select group of particularly interesting texts. Subjects include: analog computers, Honeywell 316, LINC, TX-2, Multics, TOPS10, SGI, Thinking Machines, etc.

An old mystery was solved for me while I was scanning the PB-250 manuals. The PB-250, a 22-bit delay-line memory minicomputer from the early 60s, has almost no front panel. That's kind of weird, because at that time pretty much all computers had a full set of lights and switches to see and control what was happening in the cpu at the absolute lowest level.

Then I ran across the section in the second volume of the PB-250 Technical Manual which explains how to view to contents of a register by hooking up an oscilliscope to the correct test points!

Vg Command Gate - Displays the delay line the current instructions are coming from.
Cs Cycle Trigger - Generates one pulse at the beginning of each machine cycle.
Cr C Register - Displays the contents of the C register.
Fg Fetch Gate - Displays memory reads.
P24 24th Pulse - Helps you scale the 22 bit word on the oscilliscope display.
Etc.