Trying to recover 67's prerecorded magnetic cards

[[kby]]

(08-17-2021 02:45 PM)aurelio Wrote:  

(08-17-2021 12:59 PM)Sylvain Cote Wrote:  Aurelio,
I have almost all the HP-65 & HP-67 application pac in my collection.
Several cards, about a dozen, are not working anymore and nothing can revive them.
Sylvain

Thank-you Sylvain (sob....)
Aaaarg..... so the only way is to write onto a new card, entering manually each line of the program, step by step and using the original card merely as overlay for the A, B,C, D,E keyes

Or find someone with a readable version of the card. Maybe list which ones you need…you might at least get some. I have several 67/97 pacs although nothing unusual.

Generally I have found magnetic fields to be the biggest culprits these days as so many devices have magnets in them. They’re not very strong ones but at close range, the cards seem to erase easily. The real bummers are the cards that can’t be keyed in snd require some special techniques to write (which abuse the card reader). I also tend to keep copies in a metal can. However, this won’t destroy the card permanently.

Magna-see (iron filings in trichloroethylene) might give you an idea if it’s a bad spot on the card or something.

Is it bad on both sides?