8-page open-access (thanks to the Computer History Museum!) IEEE #PDF #paper from 1959 on #magnetic-logic #hardware, “Square-Loop Magnetic Logic Circuits”, by Edward P. Stabler. Also mentions #ferroelectric capacitors, saying they are equivalent; this seems very promising for higher-frequency and smaller-dimension systems! Covers the physics from first principles, including the threshold, memory, and saturation properties of ferromagnetic materials (in general, not giving any actual numbers). Gives equivalent circuits, describes how to compose logic elements. “It is clear from the discussion that theoretically a single flux-steering gate can generate any combinational logic function.” Also describes how to use a network of simple toroidal cores to replicate all of the above. Unfortunately the scanned oscilloscope photographs are of quality too poor to read unambiguously. Includes a kind of “magnetic diode” that must be reset after use. #toread
Jeri Ellsworth #video on #magnetic-logic #hardware with some oscilloscope demos. Cites 1961 book “Square-loop ferrite circuitry”, by C. J. Quarterly (? Maybe Quartly 1962?), which I can’t find.
#PDF of Lubomyr S. #Onyshkevych’s 1957 “Analysis of Circuits with Multiple-Hole Magnetic Cores”, MIT tech report 329, a 70-page master’s thesis #paper on multiple-hole #magnetic-logic #hardware, aka “transfluxors”, which Onyshkevych credits to Jan A. Rajchman at RCA Labs. “Diodeless operation of a transfluxor circuit was found to be possible, but slow, unreliable, and critical.” Very poorly scanned photos. Mentions that square-loop ferrite (remanent flux/saturation flux ∈ [0.9, 0.95]) is usually MgMn ferrite (which I think is magnesium-manganese oxide). A one-core full-adder with five holes is shown on p.32 (the 38th of 70 pages); the next page has a three-hole “magnetic SPDT switch”. A “very short rise time” for a current pulse is glossed as “<0.1 μsec”. None of the references are in Russian or Ukrainian. #toread #history
US patent 4,201,965 from 1978 by Lubomyr #Onyshkevych, who did his master’s thesis in 1957 on #magnetic-logic and apparently then went to go work at RCA. It’s about building inductors into PCB #hardware. #patents
#Onyshkevych wrote this entry for the 1993 “Encyclopedia of Ukraine” about a little-known (mostly) 19th-century Galician physicist who, apparently, discovered X-rays before Roentgen but failed to publish, and also wrote extensively on “the Ukrainian question”. From this we can perhaps infer that Onyshkevych is Ukrainian, and perhaps his family fled to the US due to the Holodomor.
The Elliott 803 #hardware used #magnetic-logic gates. #history
#hardware amplifier from 1916 using magnetic saturation, a precursor of #magnetic-logic. However, the (public-domain!) paper isn’t open-access. Sci-hub comes through. The paper is spelled entirely without “-ugh”. Photos scanned at high quality. Touts possible application to “high-speed automatic telegraphy” over radio waves, transmitting “from 500 to 1,500 words per minute”. #history #toread
[kos] developed #magnetic-logic #hardware in 2013 without using square-loop ferrite, but his diagrams and/or photos have been lost.
Discussion thread on #magnetic-logic #hardware #history.
1961 survey #paper by John Haynes on #magnetic-logic. #toread #history
The STEMTera #Arduino breadboard #hardware site. It got Kickstarted and is on sale for US$45 at Sparkfun.
#ebook with #Proce55ing #explorable-explanations of how to do different kinds of #graphics and physics effects in code
cross-stitch embroidery pattern generation software (-as-a-service) from raster images. Doesn’t dither or do a heck of a lot of palette optimization, as far as I can tell.
Toner cartridge refills are legal under #USA #law according to a new US Supreme Court opinion in Impression v. Lexmark; patent rights exhaust at first sale, reversing a Federal Circuit decision. This decision also legalizes importing patented “grey market” cartridges, as long as they were sold by the patentee, which will likely have a major impact on pharmaceutical markets. The decision was nearly unanimous, except that Ginsburg dissented in part and Gorsuch abstained.
#history of #Unix #filesystems and their reliability