[GreenKeys] M28 reperfs

[Duncanancy]

Photoelectric readers! Yes, that is probably the reason.(I knew there had to be a reason)Thanks, Duncan K2OEQ Sent from my Kleinschmidt TT-4/TG, the US Army's first portable digital communications device, 1950-1980
-------- Original message --------From: "Jones, Douglas W" <douglas-w-jones at uiowa.edu> Date: 6/4/25  22:07  (GMT-05:00) To: Duncan Brown <duncanancy at earthlink.net>, Daniel Jones <djones at k6yic.com> Cc: Green Keys <greenkeys at mailman.qth.net> Subject: Re: M28 reperfs From: Duncan Brown <duncanancy at earthlink.net> -- Wednesday, June 4, 2025 8:45 PM> What is strange (to me) is that they started out chadless and then went to full perf ...> Does this imply a problem with the chadless tape?I am only guessing, but the high-speed photoelectric paper-tape readers that were commonly used with computers starting in the 1960s were really bad at reading chadless tape.  Any time you had a TTY punching tape that was then read by a computer, you probably wanted full-perf tape.I have or have had several photoelectric readers from the 1960s and 1970s.  None could read chadless tape.  The ones made in the 1970s tended to mechanically trivial, just a stepping motor directly driving the feed sprocket, a tape guide and LED/phototransistor read head.  Way simpler (and cheaper) than Teletype's complex mechanisms that pushed sensing fingers up through the holes in the tape.              Doug
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20250605/6c6a8c0f/attachment.html>