Search results
Results from the WOW.Com Content Network
HP-19C calculator HP-29C with AC-powered battery charger. The HP-19C and HP-29C were scientific/engineering pocket calculators made by Hewlett-Packard between 1977 and 1979. They were the most advanced and last models of the "20" family (compare HP-25) and included Continuous Memory (battery-backed CMOS memory) as a standard feature.
The calculator uses the proprietary HP Nut processor produced in a bulk CMOS process and featured continuous memory, whereby the contents of memory are preserved while the calculator is turned off. [13] Though commonplace now, this was still notable in the early 1980s, and is the origin of the "C" in the model name.
Button, coin, or watch cells. A button cell, watch battery, or coin battery is a small battery made of a single electrochemical cell and shaped as a squat cylinder typically 5 to 25 mm (0.197 to 0.984 in) in diameter and 1 to 6 mm (0.039 to 0.236 in) high – resembling a button.
The calculator is also powered by two CR2032 batteries. The test menu (Off, g + ↵ Enter + ON ) officially offers three choices. A fourth choice ( 4 ) is undocumented and permits to enter two hidden modes: "15.2" (more memory, but with some limitations like 8×8 inversion matrices and three-digit step number display) and "16" (emulating a HP ...
If the battery simulator has a current limit feature and if the current exceeds the maximum set value, the simulator automatically increases the voltage to limit the current [3] The advantage of using a battery simulator is its ability to freely set the emulated battery voltage to any value in order to test the charger.
HP-19B, introduced on 4 January 1988, along with the HP-17B, HP-27S and the HP-28S, and replaced by the HP-19BII (F1639A) in January 1990, [2] was a simplified Hewlett Packard business model calculator, like the 17B.
−1: If the subtraction button − is pressed after the multiplication ×, it is interpreted as a correction of the × rather than a minus sign, so that 4 − 5 is calculated. 20: If the change-sign button ± is pressed before the 5, it isn't interpreted as −5, and 4 × 5 is calculated.
The calculator is powered by two CR2032 button cells connected in parallel, which it is advised to replace one at a time, to avoid memory loss. [ 7 ] It was initially supplied with a hard zippered clamshell case with a pocket for notes, and a printed manual, [ 10 ] but this was later changed to a slipcase made of vinyl-covered cardboard with ...