Notes: "In the late 1960s, Monroe was hurting. They were a long-time maker of very good mechanical calculators, but their products looked like antiques next to the relatively new desktop electronic calculators from Wang, Sony, Friden, and Busicom. Meanwhile, Compucorp, a division of Computer Design Corporation (itself a spinoff of Wyle), was shopping around their new line of electronic calculators. Compucorp had no retail sales or distribution organization, so they were looking for an OEM relationship with an established retailer. When they met Monroe, the marriage was executed in record time. Compucorp also had OEM relationships with Dietzgen, SCM, and Seiko. Monroe sold electronic calculators designed and built by Compucorp under the Monroe name from 1969 until the HP-35 had well and truly put a stake through the heart of large, expensive (1.5 to 3 times the cost of an HP-35), desktop scientific calculators, which was approximately 1974. In the short life of these machines, the Compucorp calculators went through no less than four redesigns, each taking advantage of the latest generation of integrated circuits. The Model 325 Scientist is from the third generation and uses a custom, Compucorp-designed 19-chip chipset (manufactured by both American Micro Systems and Texas Instruments), which was essentially a general purpose microcomputer. Pretty impressive considering that was the era of dozens of transistors per IC, not billions. In addition to the Scientist, other models were made for finance, surveying, and statistics, differing only in the firmware and key labels. The calculator was fully programmable, and numerous peripherals could be connected, including a cassette tape drive for program storage. There is a pull-out quick reference card just under the keyboard with program codes. The third generation machines also saw Compucorp finally abandon nixie tubes and switch to gas-discharge seven-segment displays. In spite of the rapid pace of technological advances in those years, the calculator is still rather large and heavy, roughly equivalent to a portable typewriter. In fairness, the third generation also saw the introduction of a “hand-held” model (“portable” would have been more accurate) powered by D-cells."