Re: HP-45 school project Message #2 Posted by Tom (UK) on 3 Feb 2003, 2:03 p.m., in response to message #1 by Michel Beaulieu
Your keyboard fix should be OK.
The display may need boosting, it depends on the current drawn by the original display and the new one which may be much more efficient at turning electrons into photons.
To be on the safe side I would make a booster circuit with either transistors or perhaps a buffer chip and dropper resistors.
If you are making all this it would probably be worth making a new power source for the display with bigger batteries or mains supply (just in case you overload the original power supplies).
I think there are HP45 circuit diagrams traced by someone, I don't know who might have these.
PS Have you been sub-contracted by HP to make a demonstrator model for the latest HP RPN calc???
|