3 ms·

Magnetic Core Memory Reborn (2011)

65 points by galaktor 14y ago

galaktor 14y ago
Detailed article (also linked on the original page) http://www.corememoryshield.com/report.html http://www.corememoryshield.com/report.html
dexen 14y ago
I wonder if read and write times on-par, or better than, DRAM's are achievable with such modern core memory. Cool project, btw :-)
- pixelbeat 14y ago
  I think it was tested at 200Kb/s throughput, but with tweaks that could be doubled
- dorianj 14y ago
  Most on-die embedded DRAM is one cycle away for a whole word (I'm not sure about arduino but I'll bet it's in the same ballpark). This uses a 500 ns pulse for each bit, so reading a 8-bit word would take 40 clock cycles (at 10 mHz)
- ChuckMcM 14y ago
  No, you can't get anywhere close to modern DRAM with this type of core memory. FRAM chips [1] which use the principle of Ferrormagnetism to retain data while power is off are fairly quick however. They can replace the typical serial flash or EEPROMs you might use to save settings, and they have the benefit of unlimited write cycles and faster (than flash) write times. [1] http://www.ramtron.com/about-us/what-is-f-ram.aspx http://www.ramtron.com/about-us/what-is-f-ram.aspx
- westbywest 14y ago
  The sheer size of the core memory, e.g. measured in millimeters, will prevent it from having access times in comparable orders of magnitude as silicon-based DRAMs, whose dimensions are measured in micrometers.
robomartin 14y ago
Neat project. Interestingly enough, I often use the core memory patent as an example of a true invention worthy of being issued a patent. If there's an invention that was, at the time, new, useful and non-obvious this was it. Here's that patent: http://www.google.com/patents/US2667542 http://www.google.com/patents/US2667542 One of my favorite examples of the opposite, that is, obtaining a patent for something that is not an invention is this MIT patent: http://www.google.com/patents/US5650704 http://www.google.com/patents/US5650704 Yes, they patented a motor connected to a spring with a force sensor to control, well, force. You know the old F = kx spring formula. Not to beat MIT to death --they do a lot of great stuff that I'll never understand-- but filing for a patent on a motor with a spring? The real joke is that the patent office granted it. Don't get me started on software patents. OT for this thread anyway.
- simulate 14y ago
  Wikipedia cites Professor Jay Forrester of MIT as the original holder of the core memory patent. I believe this is the patent from Forrester: http://www.google.com/patents?id=MNxYAAAAEBAJ&pg=PA1&source=gbs_selected_pages&cad=2#v=onepage&q&f=false http://www.google.com/patents?id=MNxYAAAAEBAJ&pg=PA1&#38... MIT and IBM entered into litigation over the patent in the early 1960s and Forrester eventually won the dispute.

65 points by galaktor 14y ago

Detailed article (also linked on the original page) http://www.corememoryshield.com/report.html http://www.corememoryshield.com/report.html

dexen 14y ago

I wonder if read and write times on-par, or better than, DRAM's are achievable with such modern core memory. Cool project, btw :-)

pixelbeat 14y ago
I think it was tested at 200Kb/s throughput, but with tweaks that could be doubled
dorianj 14y ago
Most on-die embedded DRAM is one cycle away for a whole word (I'm not sure about arduino but I'll bet it's in the same ballpark). This uses a 500 ns pulse for each bit, so reading a 8-bit word would take 40 clock cycles (at 10 mHz)
ChuckMcM 14y ago
No, you can't get anywhere close to modern DRAM with this type of core memory. FRAM chips [1] which use the principle of Ferrormagnetism to retain data while power is off are fairly quick however. They can replace the typical serial flash or EEPROMs you might use to save settings, and they have the benefit of unlimited write cycles and faster (than flash) write times. [1] http://www.ramtron.com/about-us/what-is-f-ram.aspx http://www.ramtron.com/about-us/what-is-f-ram.aspx
westbywest 14y ago
The sheer size of the core memory, e.g. measured in millimeters, will prevent it from having access times in comparable orders of magnitude as silicon-based DRAMs, whose dimensions are measured in micrometers.

robomartin 14y ago

Neat project. Interestingly enough, I often use the core memory patent as an example of a true invention worthy of being issued a patent. If there's an invention that was, at the time, new, useful and non-obvious this was it. Here's that patent: http://www.google.com/patents/US2667542 http://www.google.com/patents/US2667542 One of my favorite examples of the opposite, that is, obtaining a patent for something that is not an invention is this MIT patent: http://www.google.com/patents/US5650704 http://www.google.com/patents/US5650704 Yes, they patented a motor connected to a spring with a force sensor to control, well, force. You know the old F = kx spring formula. Not to beat MIT to death --they do a lot of great stuff that I'll never understand-- but filing for a patent on a motor with a spring? The real joke is that the patent office granted it. Don't get me started on software patents. OT for this thread anyway.

simulate 14y ago
Wikipedia cites Professor Jay Forrester of MIT as the original holder of the core memory patent. I believe this is the patent from Forrester: http://www.google.com/patents?id=MNxYAAAAEBAJ&pg=PA1&source=gbs_selected_pages&cad=2#v=onepage&q&f=false http://www.google.com/patents?id=MNxYAAAAEBAJ&pg=PA1&#38... MIT and IBM entered into litigation over the patent in the early 1960s and Forrester eventually won the dispute.