Home
Dave

Blog
Archives
By Subject

Recent:

RCS Online Library
All I Remember of Earth
Moth
Lichens
On Copper Wings
Paper Nautilus
Curves
Another Moth Wing
Monkey Child
Antenna
Fly Eye
Leonor Fini
Dandelion
Moth Wing
Thing
MDF
MXBX AS220 II
BSD Hunt
Pipilotti Rist

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.