The HP-25 was a hand-held programmable scientific/engineering calculator made by Hewlett-Packard between 1975 and 1978. The HP-25 was introduced as a cheaper (US$195) alternative to the ground-breaking HP-65, the first handheld programmable calculator. To reduce cost, the HP-25 omitted the HP-65's magnetic card reader, so it could only be programmed using the keyboard. After switching off, the program was lost and had to be typed in again. The model HP-25C, introduced in 1976, addressed that issue through the first use of battery-backed CMOS memory in a calculator, termed continuous memory by Hewlett-Packard.

The HP-25C had 49 lines of programmable memory. It used reverse Polish notation entry, and had eight registers. It had a 12-digit LED display. The HP-25C cost $200, and the HP-25 was reduced to $150 following the introduction of the HP-25C.

Kindly donated by Francis Hookham

Manufacturer: Hewlett-Packard
Date: 1976

This exhibit has a reference ID of CH31347. Please quote this reference ID in any communication with the Centre for Computing History.

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