Hewlett Packard 9100B
The HP 9100 is the first calculator Hewlett Packard produced in the late 1960’s. This extremely interesting machine does not contain any digital circuits. The magnetic core memory uses a small CRT display screen, which displays three rows of characters.
We have a copy of HP 9100 just here at PEEK&POKE Computer Museum, which was a generous donation of company Rijekaprojekt who used it for years and years. The machine still works perfectly.
More information on website of HP Museum.