HP-65 more on the card reader

[teenix]

(01-31-2019 01:20 PM)albertofenini Wrote:  I think you are right, A could be the candidate,
However, what fails me is is the following.
Once the upper left corner has gone past the switch i.e. 3 o 4 mm max, there is no difference between a protected card or a non protected card, since the shape is same.
What I'm trying to say, is that the difference between a protected card and non protected card is what ? that switch closes (or open ?) a little before o a little after ?
How can I catch that ?
take care Alberto

The switch will activate a little later write protected than it would have not write protected which is how the CRC detects the condition. It would be fiddly, but connecting an ohmmeter as mentioned earlier should detect the switch operation if a card is manually pushed across the activating balls. You should be able to test all 4 CRC pins one at a time while pushing the card in a little at a time.

cheers

Tony