Has anyone heard about Magnetic Logic from the days of yore?Good Grief, I've been receiving all sorts of feedback on my Reinventing the Computer article and my Heath Robinson Rube Goldberg Computer blog on Monday 27 March, 2006.
With regard to my idea of using a panel of antique switches to represent a portion of the ROM, for example, one reader emailed me to say: Sure, an arrangement of switches makes perfect sense. You can point to the example set by no less than Seymour Cray, in the CDC 6600 'Deadstart Panel' – what we'd call a 'boot ROM' these days.
He also pointed me toward a Yahoo Newsgroup called "HowThingsWork" which gave a reference to a book on designing logic with relays called: The Design of Switching Circuits by Keister, Ritchie, and Washburn (this Ritchie is the father of Dennis Ritchie, co-creator of Unix.) Of course I immediately bounced over to Amazon to discover that there were only three copies available in the "Used Books" section (there are only two now because I have one winging its way toward me as we speak).
Another reader emailed me saying: "Back in the mid-60's, either Electronics Illustrated or Popular Electronics had a cover article on using neon bulbs to make an adding machine. Seems to me that this would be a good one for the RAM for your proposed machine, being both retro and giving a visual indication of the memory contents." He then went on to say: "Yet another logic device was the magnetic logic used in the Univac SS-80 and SS-90 computers."
Magnetic Logic? I've never heard of this! Does anyone know anything more about this technology? Also, does anyone have a copy of the magazine(s) containing the "neon tube adding machine" article? I'm going to be adding all of these ideas to the more detailed, ongoing version of this project / idea / thingy in the HRRG Computer paper on my own website.