National Semiconductor 4640
The National Semiconductor 4640 is a scientific calculator with RPN (reverse polish notation) logic. It has 36 keys, and an LED (light-emitting diode) display typical of calculators of this era. The power source is Sealed battery pack.
Facts at a glance:
| Feature | Value |
|---|---|
| Type | Scientific |
| Keys | 36 |
| Logic | RPN |
| Display type | LED |
| Length | 150mm |
| Width | 75mm |
| Thickness | 31mm |
| Power Source | Sealed battery pack |
Replacements:
If you have a National Semiconductor 4640 that is no longer working, you can consider replacing the calculator with a modern equivalent.
We suggest the following current model as a replacement: