Rodney, Oddly enough, I see the photos attached.
re: a mechanical delay line My dad worked for IBM way back in the day, as an electrical engineer. He left me copies of a few of the patents on which he was listed as an inventor. One of them is exactly such a device, used at the edge of telephone switching networks (I think - edge of some network anyway) to hold state. Much cheaper than core memory for the time, and could hold 2048 bits, with a latency of something like 50ms. Somewhere I have the paperwork for the patent application. Now I'm curious if it was a refinement or the first of its type. Never thought about it before. But this is one where he had kept a physical example, one they had to cut open during testing. I knew exactly where it was so I just snapped a photo with my phone: http://mackies.org/mechanical_delay_line_dynamic_memory_ibm.jpg Figured it would be interesting to see and compare. Rob. On Sun, Aug 9, 2020 at 6:14 PM Rodney Radford via TriEmbed < [email protected]> wrote: > Nevermind, the photos 440k were deemed too large to be sent by the > TriEmbed server. > > Sorry you will not be able to see them. > > > On Sun, Aug 9, 2020 at 5:38 PM Rodney Radford <[email protected]> > wrote: > >> I forgot to include the photos... >> >> >> On Sun, Aug 9, 2020 at 5:37 PM Rodney Radford <[email protected]> >> wrote: >> >>> One of the passions I have put time in the last few months are >>> collecting and learning about old vintage computers. >>> >>> I currently have: >>> * IMSAI S-100 system >>> * Sol-20 S-100 system >>> * TRS-80 Model 1 and 4p >>> * Two Apple IIe systems >>> * Kaypro 10 luggable system >>> * TI 99/4 >>> >>> I used to have a much larger collection including >>> * Burroughs L5000 (google about that beast) >>> * TRS-80 Model 2, 3 and 4 >>> * Zerox CP/M system (I think I still have it, but can't find it) >>> * Pet Commodore 2001 (loaned to a 'friend' - never got it back) >>> * several Apollo systems >>> >>> While I wish I could have kept all the old systems, it just was not >>> possible due to storage space constraints. >>> >>> Back in highschool, a teacher gave me her old 4-function Singer (yes, >>> the sewing machine) calculator. I, of course, took it apart... ;-) >>> >>> I did keep two parts from the calculator - the keyboard (mechanica >>> marvel) and the storage device (a mechanical delay line). >>> >>> When I first looked inside, I saw the aluminum box with the words read >>> amp and write amp on it, and I *knew* I had found core memory. Then I >>> opened it and was completely surprised with what I found. It is a >>> magnetostrictive delay line memory device - memory was stored by twisting >>> the wire at one end, and the twist would propogate through the long coil >>> and out at the other end. By varying the direction of the twist, data could >>> be stored temporarily, and it was then sent back in again for storage again. >>> >>> The other item I kept from the calculator was the keyboard. On each >>> keypress, the key was decoded with gears and levers that move magnets over >>> reed relays - as that was more economical than a simple electronic keyboard >>> decoder. >>> >>> >>> Here is a link to information about the calculator (and some info on the >>> delay line): >>> >>> >>> https://www.oldcalculatormuseum.com/friden1160.html >>> <https://www.oldcalculatormuseum.com/friden1160.html?fbclid=IwAR1jtFCm3O_oRCn_hLop43h5fNOtefDedwSv1hVtzH7vUv_TSvCC4qqGjEs> >>> >>> >>> Photos included of the delay line and keyboard. If we were meeting in >>> person Monday, I would have brought them out for show and tell. >>> >>> I also really enjoyed the virtual vintage computer festival I mentioned >>> earlier. Some really good talks on that, and my first of four books I >>> ordered arrived today - the ENIAC Technical Reference manual, as written by >>> one of the first female programmers on it. >>> >>> >>> PS: If you have any old systems that need a home let me know. I really >>> should have grabbed the TRS-80 Model 100 that I brought last year that was >>> given to the club, but I let someone else take it (any idea who grabbed it?) >>> >>> >>> Anyway, back to current time where I need to finish up an IoT device for >>> work... ;-) >>> >>> >>> _______________________________________________ > Triangle, NC Embedded Computing mailing list > > To post message: [email protected] > List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org > TriEmbed web site: http://TriEmbed.org > To unsubscribe, click link and send a blank message: mailto: > [email protected]?subject=unsubscribe > >
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