4 ms·

I've always wanted to do this! Maybe I'll make the rope memory version. https://en.wikipedia.org/wiki/Core_rope_memory https://en.wikipedia.org/wiki/Core_rope_

• walrus01 10y ago
  That's great how there is a measurement of 2.5MB per cubic meter. I've love to see a 1 x 1 x 1 meter cube of rope memory... Imagine the person hours required to do something like that, you'd have to hire professional persian carpet weavers or something.
  • robryk 10y ago
    > Imagine the person hours required to do something like that, you'd have to hire professional persian carpet weavers or something. Apollo Guidance Computer (the computer of the Apollo Command Module) has 36K 16-bit words of core rope memory. That is about 0.5MB. There were at least ten such computers created. So, this much core rope memory was woven for the Apollo Command Module's computers alone. See a previous discussion: https://news.ycombinator.com/item?id=7656282 https://news.ycombinator.com/item?id=7656282
• Animats 10y ago
  The original version of that was the Dimond ring translator for #5 crossbar.[1] The purpose of this device was to translate a line position in the switching system to the phone number for billing purposes. It was a big ROM which could be manually changed by moving wires. This allowed some phone number portability - if you moved within the same central office area, you could keep the same phone number. It shows how hard it was to make a memory device in the 1950s. For a long time, that was the bottleneck in computing. Electronic arithmetic units date from around 1940, but memory devices that didn't suck only came in around 1965, and didn't get cheap until around 1990. [1] http://etler.com/docs/Crossbar/articles/30-AMATranslator.pdf http://etler.com/docs/Crossbar/articles/30-AMATranslator.pdf