HP-67 1705A01234 [erase other's cards, writes and sometime read back its own cards]

[teenix]

(11-21-2021 12:43 AM)albertofenini Wrote:  Thanks Tony
I’ll surely check it
Still, it fails me how is it possible that just reading a card can damaged it
so that any other unit, including the one that has originally recorded it, will
not be able to read it again …
I’ll check it better tomorrow and let you know

When you says “make sure WE stays low” you mean it has to be ground connected right?
And when it should go low and how long it should stay low ?

Thanks !!!

WE stays Logic LO when reading and probably stays LO all the time when idle. If it goes Logic HI, the write circuits become active which is undesirable for any other mode than writing. If WE goes HI when reading, it will affect the stored card data.

cheers

Tony