Memodyne M80 Digital Cassette Recorder

Tapley, Mark mtapley at
Tue May 10 08:03:32 CDT 2016

On May 10, 2016, at 1:12 AM, jwsmobile <jws at> wrote:

>  IIRc there was a Silent 700 that had cassettes?  Or was it the KSR version of the 800 dot matrix TI printers?

I actually got to use one of these or one similar for a while:

Back in high school, while working at University of Texas Center for Space Research. We had a line from the NASA laser-ranging network which ran into the TI which recorded anything incoming onto its cassette. I’d come in in the morning, switch the TI connection to an RS-232 into the PDP-11, and play back the tape onto the “gargantuan” hard drive, then change to a new tape and archive (put into a box) the old one.  The PDP-11 would later send a week or more worth of observations to the campus CYBER to determine the orbit of whatever satellite was being tracked (usually LAGEOS, also Starlette and BE-2 (sic?).)

The setup got replaced eventually by a CP/M system with 2 8” floppies (Balcones Computer Corporation, according to the box. I have never seen another one of those….). Accustomed as I was to the 5.25” floppies on my TRS-80, I walked into the lab the day after the new CP/M box was installed - and my jaw fell open. The 8” drives just kept running! No spin-down when not being accessed! Luckily someone was there to explain that that was actually by design, I didn’t need to shut down the box to keep from wearing out the disks.

Fun times.

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