An improved version of the HP-25 featuring continuous memory. Programs and data were retained when the calculator was turned off, because the new low power CMOS memory was powered even in the "off" state. It was even possible to change the battery pack and retain the memory because of a capacitor inside.

The model HP-25C, introduced in 1976, addressed that shortcoming through the first use of battery-backed CMOS memory in a calculator, termed continuous memory by HP. Like all early HP calculators, the 25 used the Reverse Polish Notation (RPN) for entering calculations, working on a four-level stack (x,y,z,t).

HP25c Calculator Emulator for the BlackBerry Storm There is a very nice Java simulation of the Hewlett-Packard HP25 calculator at the online Museum of HP Calculators . Doug Braun did an excellent job porting it to the BlackBerry Storm, but sadly got a new cell phone – a Droid X – so he is no longer planning any more Blackberry software ...

USING CONTINUOUSMEMORY WhenyouturnoffyourHP-25C,the calculatorretains information stored in the: = 49-step program memory, = 8 addressable storage registers,

Fortunately, Larry Leinweber has written a java simulation. Manual Available. HP-25 features. Technology and Packaging. Dimensions and Weight. Programming Information. Price: $195. The price reduced to $145 when the HP-25C was introduced. Introduction-Discontinuation: 1975-1978.

Free download of a color scan of the English-language document 'Getting The Most From Continuous Memory (HP-25C)' by Hewlett-Packard, which is a document for the HP-25 calculator.

msp430 Based Calculator Emulator for the HP-21, HP-25C, and HP-33C Calculators. This is a hardware realization of Eric Smith’s Nonpareil microcode simulator. The objective of the project is to re-create popular 70’s RPN calculators such as the HP Woodstock and Spice series.

Mar 5, 2019 · We are dealing with mainly two issues : the motherboard and the keyboard. As said before we have opened the working HP25C from our collection, and measured Vgg, Vss and Vdisp. They were obviously corrected. Looking at Jaques Laporte scheme we tried to find where to measure the Vgg, Vss and Vdisp at the PSU.

Aug 26, 2012 · Download HP25c - BlackBerry Storm RPN Calculator for free. This application emulates an HP25c RPN calculator on a BlackBerry Storm/Storm 2. It is 100% compatible with the classic pocket calculator of the late 1970s, is fully programmable, and will include a program librarian to save and recall user programs.

The HP 25C handheld calculator was Hewlett-Packard’s first programmable handheld product with “continuous memory,” meaning that it could retain information after the device was turned off without requiring a memory card. Hewlett-Packard would continue to use the “C” designation to denote continuous memory.