core memory
in [Design]
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From: PeterD on 5 Dec 2009 20:10 On Sat, 05 Dec 2009 19:18:45 +0000, ChrisQ <meru(a)devnull.com> wrote: >Jan Panteltje wrote: >> On a sunny day (Sat, 05 Dec 2009 10:51:36 -0800) it happened John Larkin >> <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in >> <kqalh59i8jsogn1t6p3ghuaop5c137qtoj(a)4ax.com>: >> >>> Testing some FTP stuff, threw up some test files... >>> >>> ftp://jjlarkin.lmi.net/Core_304bits.jpg >> >> 16 bits x 19?? >> >> >>> ftp://jjlarkin.lmi.net/Core_4K.jpg >> >> Amazing.. >> >> >>> ftp://jjlarkin.lmi.net/Core_4Kdetail.jpg >> >> Must have been expensive. >> >> >>> John >>> >>> >>> > >Don't recognise either of those as to manufacturer, but the last machine >that I had with core was an early pdp11/05, which eventually got shipped >back to the us. I still have a PDP 11/05 core unit hanging on my wall along witg a disk platter and a few other things from that machine. > >Ok, quiz time: how does core memory work ?. (and no cheating via google >etc :-)... > >Regards, > >Chris
From: krw on 5 Dec 2009 21:39 On Sat, 05 Dec 2009 14:09:24 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sat, 05 Dec 2009 19:03:54 GMT, Jan Panteltje ><pNaonStpealmtje(a)yahoo.com> wrote: > >>On a sunny day (Sat, 05 Dec 2009 10:51:36 -0800) it happened John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in >><kqalh59i8jsogn1t6p3ghuaop5c137qtoj(a)4ax.com>: >> >>>Testing some FTP stuff, threw up some test files... >>> >>>ftp://jjlarkin.lmi.net/Core_304bits.jpg >> >>16 bits x 19?? >> >> >>>ftp://jjlarkin.lmi.net/Core_4K.jpg >> >>Amazing.. >> >> >>>ftp://jjlarkin.lmi.net/Core_4Kdetail.jpg >> >>Must have been expensive. >> >> >>>John >>> >>> >>> > >I remember when IBM announced that they had reduced the price of >mainframe core to below $50,000 per megabyte. I was very young at the >time, of course. That must have been semiconductor memory.
From: krw on 5 Dec 2009 21:41 On Sat, 05 Dec 2009 14:05:33 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sat, 05 Dec 2009 13:33:53 -0800, Joerg <invalid(a)invalid.invalid> >wrote: > >>John Larkin wrote: >>> Testing some FTP stuff, threw up some test files... >>> >>> ftp://jjlarkin.lmi.net/Core_304bits.jpg >>> >>> ftp://jjlarkin.lmi.net/Core_4K.jpg >>> >>> ftp://jjlarkin.lmi.net/Core_4Kdetail.jpg >>> >> >>Here I must confess that I cruelly re-purposed some of those. People >>made matrix keyboards with them because the hysteresis provided an easy >>way to avoid contact bounce (you had to reset the cores before the next >>keystroke was accepted). So, snip, snip, snip, clicker, clicker, into a >>bag and gave them away. Back in the 70's keyboards with German layout >>were very expensive, some had odd interfaces, and buying 30-40 push >>button switches was a lot cheaper. You could buy them with a step and >>then glue a label onto the lower step. I think they still make them. > >There were some jukeboxes that used core memory - BIG cores, one per >record - to remember which records had been selected/paid for to play. ....and weren't embarrassed to collect twice for the same tune.
From: John Larkin on 6 Dec 2009 00:01 On Sat, 05 Dec 2009 20:41:05 -0600, krw <krw(a)att.bizzzzzzzzzzz> wrote: >On Sat, 05 Dec 2009 14:05:33 -0800, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Sat, 05 Dec 2009 13:33:53 -0800, Joerg <invalid(a)invalid.invalid> >>wrote: >> >>>John Larkin wrote: >>>> Testing some FTP stuff, threw up some test files... >>>> >>>> ftp://jjlarkin.lmi.net/Core_304bits.jpg >>>> >>>> ftp://jjlarkin.lmi.net/Core_4K.jpg >>>> >>>> ftp://jjlarkin.lmi.net/Core_4Kdetail.jpg >>>> >>> >>>Here I must confess that I cruelly re-purposed some of those. People >>>made matrix keyboards with them because the hysteresis provided an easy >>>way to avoid contact bounce (you had to reset the cores before the next >>>keystroke was accepted). So, snip, snip, snip, clicker, clicker, into a >>>bag and gave them away. Back in the 70's keyboards with German layout >>>were very expensive, some had odd interfaces, and buying 30-40 push >>>button switches was a lot cheaper. You could buy them with a step and >>>then glue a label onto the lower step. I think they still make them. >> >>There were some jukeboxes that used core memory - BIG cores, one per >>record - to remember which records had been selected/paid for to play. > >...and weren't embarrassed to collect twice for the same tune. Exactly. But if some yahoo pulled the plug out of the wall, as they were wont to do, and it was replaced, the request wasn't lost. John
From: Robert Baer on 6 Dec 2009 02:37
John Larkin wrote: > Testing some FTP stuff, threw up some test files... > > ftp://jjlarkin.lmi.net/Core_304bits.jpg > > ftp://jjlarkin.lmi.net/Core_4K.jpg > > ftp://jjlarkin.lmi.net/Core_4Kdetail.jpg > > John > > Can't be government because it is not Air Corps.. |