[GreenKeys] BRPE feeds tape!

[Jones, Douglas W]

I managed to get the BRPE I've been working on to feed tape, possibly for the first time this century.  I still need to get or make an 8-bit punch block, but the clatter of the mechanism feeding at 110 characters per second (and moving tape at 11 inches per second) is impressive.  I took a photo, see this log entry:
-- https://homepage.cs.uiowa.edu/~jones/pdp8/UI-8/log2025.shtml#2025-04-10

That's my finger in the photo holding down the feed lever.  The linkage that does the tape feed has to be one of the most impressive kluges I've ever seen.  Quite a contrast to the very elegant knee-joint punch linkages of the machine.  Yes, there's a knee joint in the drive train for the feed ratchet, but everything beyond that joint is just a bit bizarre.

By the way, the BRPE patent is an interesting read:
-- https://patents.google.com/patent/US2675078A

It's interesting how the knee-joint mechanism is clearly documented in that patent, but by the time it got into the BRPE, they'd inverted the knee, added drag links, and added the eccentric bail.  (There's a second BRPE patent that is only used on early models, replaced by the magnet and inductive pickup for the timing pulse on later models.)

           Doug Jones