I've got a HP41 module which I've got an inkling as to what it is but not how I could use it/what it is good for.
The module has a clear window with what looks like an EPROM showing through. There are no identifying marks or text on the module, although "828/89" has been lightly scratched next to the EPROM window.
When I plug the module into my 41cv and turn the unit on, a message "ZEPROM TEST" appears on the display and the numeric flag annunciators turn on in turn (1, 2, 3 & 4) with each displayed for 8 or so seconds. Finally a "TESTS PASSED" message is displayed and a keystroke allows normal operation of the calculator.
I don't notice any changes in any of the catalog listings (although I've not inspected the CATALOG 0 listing in any detail).
A google for ZEPROM isn't overly helpful.
Can anyone tell me what I've got and how to use it?
I don't have a programmer so I doubt I'll be able to do much with it.
- Pauli