Trying to recover 67's prerecorded magnetic cards

[aurelio]

(08-22-2021 02:40 AM)[kby] Wrote:  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?

Actually never I cared too much about the letal presence of magnetic fields due to common electrical devices used daily at home,I've not permenent magnets in my home, and I always kept calculators and related stuff, safely and not near even to speakers, as I can remember but I will follow right now, the advice to keep them into a metal box...it's surely better this way
I'm not the first owner of this pack, it came years ago with a 67 wich I bought in the US and tried to repair (card reader issue) and I got definitively succes with the help of a friend of mine really skilled in repairing this and other machines like the HP97.
meanwhile I had tested the pack with the help of 41's, 97 or another 67, finding that part of the cards was defective.
Maybe not the entire package but a few cards (the ones in the first holder maybe), could been left exposed to a magnetic field, by the previous owner, I don't know it actually I thought it could be just a problem of oxidation.

These cards are bad on both sides, I think , 'cause I get "Error" reading on both the sides...

Edit: typos