8 ms·

This is pretty cool by itself of course. But I'm wondering, is there any reason at all to use core memory today? I know EMP/disaster resistance has been said in

This is pretty cool by itself of course. But I'm wondering, is there any reason at all to use core memory today? I know EMP/disaster resistance has been said in the past, but a small modern durable chip encased in a bunch of protection should work better right?

moftz 9y ago
There are plenty of rad hard memory solutions out there that have modern interfaces and take up no space relative to the size of core memory. Core memory is a thing of the past and shouldn't ever really be part of anyone's modern designs. You can get rad hard RAM, EEPROM, and NV Flash today for space and military applications, for a price [1]. If you want disaster-proof offline backup, a below ground water-proof storage locker bolted to the foundation with a faraday cage inside is more than enough. Dig deeper if you want it to survive a nuke. [1] http://www.3d-plus.com/product.php?fam=8 http://www.3d-plus.com/product.php?fam=8
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

moftz 9y ago

There are plenty of rad hard memory solutions out there that have modern interfaces and take up no space relative to the size of core memory. Core memory is a thing of the past and shouldn't ever really be part of anyone's modern designs. You can get rad hard RAM, EEPROM, and NV Flash today for space and military applications, for a price [1]. If you want disaster-proof offline backup, a below ground water-proof storage locker bolted to the foundation with a faraday cage inside is more than enough. Dig deeper if you want it to survive a nuke. [1] http://www.3d-plus.com/product.php?fam=8 http://www.3d-plus.com/product.php?fam=8

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