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The only competitor core has for eternally non-volatile low tech near radiation proof infinitely rewritable electrical data storage is latching relays and each

by VLM 9y ago

The only competitor core has for eternally non-volatile low tech near radiation proof infinitely rewritable electrical data storage is latching relays and each bit of latching relay is huge in comparison to core. Also latching relays unlike core has moving parts that will eventually wear out. A million cycles sounds like a long time for a latching relay to live, but as a register or memory for a computer at 0.1 Hz thats only two months or so. So if you want to use latching relays you're limited to applications where the system will never perform more than a couple hundred thousand bit flips. The marketplace for eternally non-volatile low tech near radiation proof no moving parts infinitely rewritable data storage is roughly nil, unfortunately. Maybe a space probe to the worst parts of Jupiter or as part of a nuclear missile warhead. "In the old days" they had to make the ferrite cores, then characterize them, then wrap them into memory units by hand, but I would imagine given enough money one could find a way to 3-d print cores around taut stainless steel wires then fire the core ceramic, automating the process. Given a very large budget of course. Its probably cheaper in practice to ship very large amounts of flash wrapped in lead shielding.

hwillis 9y ago
>The only competitor core has for eternally non-volatile low tech near radiation proof infinitely rewritable electrical data storage is latching relays except for tape >The marketplace for eternally non-volatile low tech near radiation proof no moving parts infinitely rewritable data storage is roughly nil incidentally google is the biggest buyer of tape in the world >I would imagine given enough money one could find a way to 3-d print cores around taut stainless steel wires then fire the core ceramic, automating the process. you are describing tape and it's predecessor wire recording. Rather than coat a wire in magnetic material they just used steel wire. They only use ceramic to make core because it's easier to fire it in an annulus than to punch out laminations that small
- Phlarp 9y ago
  Radiation.
- VLM 9y ago
  You bring up a fair point but tapes not really infinitely rewritable. You can take something like a 60's PDP-8 and write a byte of data to the same core address 333 thousand times per second for at least half a century and it'll be fine. In my head that's a 14 or 15 digit number of writes which no tape or even flash memory can withstand. In theory much like a hard drive head floats on an air bearing over the platter it should be possible given enough development time and money to make a tape head that floats and never quite touches tape. I worked at a place in the 90s that had IBM floating tape transport where compressed air maintained some loops bouncing in channels to make sure the tape was never snapped taut and therefore stretched but I'm taking about actually floating a non-contract head which AFAIK has never commercially shipped for tape (although it would be cool to be proven wrong). I was going to bring up how tape can throw oxide after a couple decades in storage but I suppose core could have dissimilar metal corrosion over the course of a century or maybe temperature cycles would stress and crack individual cores after a couple centuries unless kept at a constant temp. Also in theory non-archival core could exist just like non-archival tape definitely exists. So fair enough on that account.
cr0sh 9y ago
There was a period in time right between core memory and solid state where something was developed (I believe by IBM) which was core memory, but layered "thin film" on either a glass or maybe polyester film substrate. It essentially gave all the advantages of core memory, but could be printed by machine to eliminate the need for hand assembly that standard core memory required. Fabrication was done using something akin to how PCBs are made, coupled with something akin to offset printing (or something like that). Information about this memory is very sparse; I've encountered a few references about it here and there on the internet, but mainly I've read about it in old computer books contemporary with the time period (mid-to-late 1960s to early 1970s). I also believe you can find an article or two in old issues of Popular Science magazine for the same period (google books has them all online). Ultimately, though, solid-state won out for many good reasons; it was a case of a technology which - had it came about 5 years or more before, would have taken over the market, but its window was too small for acceptance (and probably there were bugs to work out). As an aside: If you like this kind of thing, it is very interesting to read about the history of these kinds of shifts in technology. To read about this history of the transition to tube technology (think about how you would represent and generate a carrier wave for radio communication before tubes existed - it was done), then to transistors, then to integrated circuits, then to surface mount from thru-hole. Then also the transition from hand-wired "rat nest" construction to printed circuits. But the real interesting parts on all of these transitions happens between the transitions (and the overlaps) - where there exist both side-by-side, plus interesting technologies developed in the transition, anticipating things, dead ends, and in some cases ideas which won't become common until much later when other technology could "catch up" (mainly for assembly or whatnot). Early integrated circuits, for instance, were actually tiny soldered devices in a "can" or on a ceramic substrate - of very few parts. But they were anticipated by the small modules done prior by companies like IBM for assembly and maintenance of computers (and even before that, with multi-component tube assemblies of an "entire radio in a tube" type devices). There were also such things as surface mount technology being used when nothing else would do: For instance in the Apollo Guidance Computers, early surface-mount technology was used to make it more robust to vibration, and also lighter weight. Also some early integrated circuit tech was used in them as well. All of these things wouldn't become common at the business or consumer level until years later - but the tech was needed ahead of time of course for the purpose; also an example of the space program of NASA pushing the tech envelope that trickled down to consumers. Check it out if you haven't already and have an interest; I've found it pretty fascinating, as you can probably tell...

by VLM 9y ago

hwillis 9y ago

>The only competitor core has for eternally non-volatile low tech near radiation proof infinitely rewritable electrical data storage is latching relays except for tape >The marketplace for eternally non-volatile low tech near radiation proof no moving parts infinitely rewritable data storage is roughly nil incidentally google is the biggest buyer of tape in the world >I would imagine given enough money one could find a way to 3-d print cores around taut stainless steel wires then fire the core ceramic, automating the process. you are describing tape and it's predecessor wire recording. Rather than coat a wire in magnetic material they just used steel wire. They only use ceramic to make core because it's easier to fire it in an annulus than to punch out laminations that small

Phlarp 9y ago
Radiation.
VLM 9y ago
You bring up a fair point but tapes not really infinitely rewritable. You can take something like a 60's PDP-8 and write a byte of data to the same core address 333 thousand times per second for at least half a century and it'll be fine. In my head that's a 14 or 15 digit number of writes which no tape or even flash memory can withstand. In theory much like a hard drive head floats on an air bearing over the platter it should be possible given enough development time and money to make a tape head that floats and never quite touches tape. I worked at a place in the 90s that had IBM floating tape transport where compressed air maintained some loops bouncing in channels to make sure the tape was never snapped taut and therefore stretched but I'm taking about actually floating a non-contract head which AFAIK has never commercially shipped for tape (although it would be cool to be proven wrong). I was going to bring up how tape can throw oxide after a couple decades in storage but I suppose core could have dissimilar metal corrosion over the course of a century or maybe temperature cycles would stress and crack individual cores after a couple centuries unless kept at a constant temp. Also in theory non-archival core could exist just like non-archival tape definitely exists. So fair enough on that account.

cr0sh 9y ago

There was a period in time right between core memory and solid state where something was developed (I believe by IBM) which was core memory, but layered "thin film" on either a glass or maybe polyester film substrate. It essentially gave all the advantages of core memory, but could be printed by machine to eliminate the need for hand assembly that standard core memory required. Fabrication was done using something akin to how PCBs are made, coupled with something akin to offset printing (or something like that). Information about this memory is very sparse; I've encountered a few references about it here and there on the internet, but mainly I've read about it in old computer books contemporary with the time period (mid-to-late 1960s to early 1970s). I also believe you can find an article or two in old issues of Popular Science magazine for the same period (google books has them all online). Ultimately, though, solid-state won out for many good reasons; it was a case of a technology which - had it came about 5 years or more before, would have taken over the market, but its window was too small for acceptance (and probably there were bugs to work out). As an aside: If you like this kind of thing, it is very interesting to read about the history of these kinds of shifts in technology. To read about this history of the transition to tube technology (think about how you would represent and generate a carrier wave for radio communication before tubes existed - it was done), then to transistors, then to integrated circuits, then to surface mount from thru-hole. Then also the transition from hand-wired "rat nest" construction to printed circuits. But the real interesting parts on all of these transitions happens between the transitions (and the overlaps) - where there exist both side-by-side, plus interesting technologies developed in the transition, anticipating things, dead ends, and in some cases ideas which won't become common until much later when other technology could "catch up" (mainly for assembly or whatnot). Early integrated circuits, for instance, were actually tiny soldered devices in a "can" or on a ceramic substrate - of very few parts. But they were anticipated by the small modules done prior by companies like IBM for assembly and maintenance of computers (and even before that, with multi-component tube assemblies of an "entire radio in a tube" type devices). There were also such things as surface mount technology being used when nothing else would do: For instance in the Apollo Guidance Computers, early surface-mount technology was used to make it more robust to vibration, and also lighter weight. Also some early integrated circuit tech was used in them as well. All of these things wouldn't become common at the business or consumer level until years later - but the tech was needed ahead of time of course for the purpose; also an example of the space program of NASA pushing the tech envelope that trickled down to consumers. Check it out if you haven't already and have an interest; I've found it pretty fascinating, as you can probably tell...