On 2017-Mar-20, at 6:58 AM, Jacek Greniger via cctalk wrote: > Hi, > > Two years ago I've found scans in PDF with the article (dated 197?, I don't > remember) describing DIY TTL-based calculator. This was microprogrammed > machine (if I remember correctly microproprogram was "stored" in the diode > array). It has LED display and possiblity to calculate square root. > Definitely not talking about EDUC-8 computer from 1975. I think this > calculator was published a little bit earlier. > > Unfortunately I'm no longer able to find it. Does anyone associate the name of > that magazine?
There's this one: http://bitsavers.trailing-edge.com/pdf/practicalElectronics/digi-cal/Digi-Cal_Jul72-May73.pdf I haven't looked at it in depth, but cursorily it looks like a way-behind-the-times (then) architecture - it looks like it's doing multiplication by exhaustive iteration, for example. One could reimplement a 1960s desktop calc design in TTL and be ahead.