Hewlett-Packard HP 21 (Woodstock PUMPKIN)
The Hewlett-Packard HP 21 is a scientific calculator with 12 digits precision and RPN (reverse polish notation) logic. It has 25 functions, 30 keys, and an LED (light-emitting diode) display typical of calculators of this era. The power source is 2xAA NiCd battery pack. A sample of this calculator is held in the calculator.org collection.
Facts at a glance:
| Feature | Value |
|---|---|
| Type | Scientific |
| Functions | 25 |
| Keys | 30 |
| Precision | 12 |
| Logic | RPN |
| Display type | LED |
| Length | 129mm |
| Width | 67mm |
| Thickness | 29mm |
| Weight | 170g |
| Power Consumption | 0.500000W |
| Power Source | 2xAA NiCd battery pack |
| Year introduced | 1975 |
| Year discontinued | 1978 |
Replacements:
If you have a Hewlett-Packard HP 21 that is no longer working, you can first try replacing the 2xAA NiCd battery pack. If that doesn't solve the problem, then you can consider replacing the calculator with a modern equivalent.
We suggest the following current model as a replacement: