HP-65 more on the card reader

[albertofenini]

Hi Harald,
we will not be able to do that, because in order to re-use the spare keyboard we had to move
the Anode and Cathode drivers, and we do not want to de-solder them again.
However, I can tell this.
In order to measure the Ph1 and Ph2 signals at the Anode driver we had to put the calc in lab mode.
We took it out of the case and we soldered a cable to from the power switch to the power line
and we added a switch in order to toggle between RUN and PRGM/WRITE modes.
With the calc in this condition, we measured Ph1 and Ph2 and they were good and clean,
both when reading or writing a card.
While at it, we measured in this condition WA and WB and to our surprise, not only they were
very clean, but the recorded program was readable and executable.
At this point, since we also have a spare case complete with keys, we mounted the unit
in this second case and it stopped to work, i.e WA was good and WB was bad.
We took the unit out of this case and it started to worke again.
By saying it works I mean is able to read and record cards, basic function has not been an issue ever
To cut it short, it the unit is out of a case it works, it reads and writes, if it is in a
case it doesn't.

Any idea with this happens ?
Thanks everyone !!!