The Tektronix Circuit Computer, a circular slide rule for layout analysis #VintageComputing @tektronix

Ed Nisley at The Smell of Molten Projects in the Morning blog writes about the Tektronix Circuit Computer. This is more like a circular slide rule than a true calculator – such were more common before electronic calculators and computers were widely available.

Following a linkie I can no longer find led me to retrieve the Tektronix Circuit Computer in my Box o’ Slide Rules:

Some searching reveals the original version had three aluminum disks, shaped and milled and photo-printed, with a honkin’ hex nut holding the cursor in place. The one I have seems like laser-printed cardstock between plastic laminating film; they don’t make ’em like that any more, either.

TEK PN 003-023 (the paper edition) runs about thirty bucks (modulo the occasional outlier) on eBay, so we’re not dealing in priceless antiquity here. The manual is readily available as a PDF, with photos in the back.

See the post for the full details.