The University of Iowa's DEC PDP-8

Restoration Log

Part of the UI-8 pages
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science



This is a chronological log of the progress restoring the University of Iowa's PDP-8 computer. Entries are added at the end as work progresses. Click on any thumbnail image to see full-sized image.

Jan 31, 2023, More R-Series logic probes

Bug 64: After a long hiatus forced on us by the COVID-19 epidemic, the retrocomputer lab was reopened during the fall of 2022. We went over many of the same ssues covered in previous years, verifying that memory didn't seem to be working and renewing our suspicion that there might be a problem with the memory strobe signal.

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Three probes
Bug 65: In doing that, we realized that we really needed more logic probes, so we set out to manufacture two more, using the design documented on Dec. 6, 2018. As with our previous probes, we packaged them in dry-erase marker bodies. The new probes all behave just like the Dec. 2018 one, differing only in the color of the caps on the markers.

In the photo

Doug Jones built one probe while Elle Goodrich and Samuel Nicklaus built the other, learning to solder and doing some logic debugging in the process, locating inadvertent cold solder joints, forgotten connections and solder bridges.