From context I figured it was sending mechanical sound impulses along the wire.
I think it would be a fun demonstration to do a storage like that but in free space, with a speaker and a microphone at a TriEmbed meeting. Tadd --- Sent from Planet X > On Aug 10, 2020, at 1:00 PM, Gregg Tracton via TriEmbed > <[email protected]> wrote: > > > > how does this delay circuit work? > is it just using the fact that signals flow down lines at 1’ per nanosecond, > so a 50’ length delays for 50 ns? > > -g > >> On Mon, Aug 10, 2020 at 9:40 AM Rodney Radford via TriEmbed >> <[email protected]> wrote: >> This is the first time I have seen another one - thanx for the photo and the >> back story. If you find the patent number, I would be interested in seeing >> it. >> >> After watching someone interface an Arduino to core memory at the virtual >> computer festival, I wondered how difficult it would be to interface an >> Arduino to this delay line. Mine has 12v stamped on the board, so that gives >> me some hint as to voltages, and the electronics on the board is simple, so >> should be possible to sketch out a schematic of the read and write circuits. >> >> >>> On Mon, Aug 10, 2020 at 3:10 AM Robert Mackie <[email protected]> wrote: >>> 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 >>>>>> >>>>>> 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 >>>> >> _______________________________________________ >> 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 >> > -- > Gregg Tracton: tired, retired & inappropriately unattired (PJ's) > _______________________________________________ > 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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