Memories Of Ages Past
The BBC has a nice little article, Weaving the way to the Moon, about building the Apollo Guidance Computer, the special purpose computer that is the ancestor of today’s fly-by-wire computer systems.
The “weaving” is concerned with the building of the magnetic core memory used in the AGC. The “cores” are actually small circular beads that have three [or more] wires passed through their center hole. You need to expand the pictures in the Wikipedia “core” article to see the lacing pattern.
The AGC used memory modules with 1024 beads, which is very time consuming to build, and the reason for hiring weavers to do the work.
2 comments
Bryan, when you and I started working with computers, all of them used core for memory.
Um, in my case, actually, all but one.
The Rice University Computer, designed and built there, completed… actually, never really completed, but the manual I still have was printed in 1962, used small CRTs with screens mounted against a circle of mica. If I recall correctly, and it’s been a long time, the bits were written in the obvious way… point the electron gun at a particular spot on the mica… and read in a similar fashion, by detecting the discharge when a spot was targeted again for reading. It never worked all that well, and they replaced the system with core at some point, but all the CRTs were still there, present but inoperative, in large Plexiglas cabinets, when I worked there in 1967.
But what can I say about the Rice Computer: it’s also the only computer I’ve ever worked with that had a crank on the front panel, and no, I’m not referring to the operator… in single-step mode, one turn of the crank executed 50 instructions.
.-= ´s last blog ..Friday Tail-Or-Two Blogging =-.
The crank would have beat the toggle switches on the minis, and the rotaries for hex on the IBM big iron.
Core was certainly more reliable than the tube based systems that were still used for special purposes in the military.