Restoring HP-65

[albertofenini]

Hi Tony thanks for your reply.

You are right, the CRC from HP-65 and HP-67 are very much different, look at this article :
HP-67 Card Reader Revisited - sydneysmith.com

What surprises me is the that first card (from the top) in the picture is for sure an original a blank HP-65 card,
while among the others there are some cards from HP-67.

I was expecting the opposite, i.e. the first card working with our HP-65 and the other three not.

We have one more unit under restoration, we hope to fix the card reader as well and then we can make some tests.

We also have four more working units, but all of them have the o-ring melted and we are running out of spare o-rings.

We also have more blank cards from different years so we can make some try.

Thanks again, take care Alberto