HP Classic Series Display Driver

[Harald]

(11-10-2016 10:31 PM)Hans-Peter Wrote:  Hi Harald

It seems to be a very interesting project, not just a display driver (more a calc driver:-).

When I started this thread it was about the original display drivers. Now it has become about a cpu board replacement for the classic series calculators. I will probably start a new thread once the board is fully working.

(11-10-2016 10:31 PM)Hans-Peter Wrote:  I have a non working HP65. There are only two segments shining.
Is there a chance to give him a new life with that Project?

That depends on what the problem is. If there is a problem with the anode or cathode drivers, I don't have a replacement for those,
If it is the main PCB, theoretically I could make a replacement PCB for that. The HP65 has a smaller PCB than the 35, 45, 70 and 80. So this would be a new design. But it wouldn't be possible (at least I would not know how) to use the card reader.

(11-10-2016 10:31 PM)Hans-Peter Wrote:  Where is now the powersupply on the new board?

The power supply is the little 5 pin IC next to the connector and the capacitors around it. This generates the supply voltage for the display driver. The two controllers run directly off the battery.

(11-10-2016 10:31 PM)Hans-Peter Wrote:  Best regards
Hans-Peter

Best Regards,
Harald