Monroe Programmable Electronic Calculator (1785)

? Several types are displayed the oldcalculator website from Rick Bensene. The 1700-series Monroe/Compucorp calculators is one that I don't have a lot of information about, but I know that they did use a very sophisticated microprocessor-like (not bit-slice) architecture, based on the later ACL chipset, which was an improvement over the earlier HTL chipset. The machines used IC-ROM-based microcode, and dynamic RAM (not static like the 2102) for main memory. The microcode determined the various functions available in the machine. Programmable and non-programmable models were available. Functionality depended on the ROM board which contained the microcode, the keyboard, and whether or not the machine contained expanded RAM. The Compucorp-designed machines of this timeframe were very advanced, and had it not been for Hewlett Packard coming out with even more advanced (albeit larger) calculators like the 9810, 9820-series, and the 9830, then later the handheld units like the HP-35, 45, and 65, Compucorp had, for a time, a good share of the high-end calculator marketplace along with HP's earlier machines (9100A, 9100B), and Wang's calculators. For the story of Compucorp and its machines, see my website essay at http://oldcalculatormuseum.com/d-compucorp.html Rick Bensene The Old Calculator Museum http://oldcalculatormuseum.com