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HP-67 - 1909S02534 - Card reader advice requested
01-27-2020, 11:26 AM
Post: #4
RE: HP-67 1909S02534 - Card reader advice requested
(01-27-2020 09:47 AM)albertofenini Wrote:  Hello Everyone,
after a bad moment in our lives with the loss of my father,
we re-opened our lab and started to work again on our toys.
Yesterday we restored an HP-67 that was in working condition but showing some wear,
you can see some pictures here :
HP-67 1909S02534 - Full restoration
However, the card reader, although rebuilt, it keeps giving an error message.
This is what RA and RB looks like :

What would you suggest to do ?
Thanks for helping us out !!!

Hi Alberto,

Indeed a sad time. Memories are forever.


The only thing I can see is the timing of the signals looks skewed. They should overlap as in the attached read image.

The idea of this approach is to provide a self clocking mechanism for more reliable data transfers.

Why it would be skewed is a mystery, but it might just be oscilloscope timing.

Does it write ok?



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RE: HP-67 1909S02534 - Card reader advice requested - teenix - 01-27-2020 11:26 AM

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