Trying to recover 67's prerecorded magnetic cards

[cahlucas]

Another thing to consider is (strong) magnetic fields. If a magnetic field, in the form of a permanent magnet, or an electrical device that creates a magnetic field, comes near the cards, all data on the cards can be disrupted or even erased. Therefore, it is best to keep the cards in a metal box, so that magnetic fields can no longer reach them. Add some moisture-absorbing granules in a cotton bag, so that the cards can no longer oxidize. I hope this will partly solve the problems with the cards. Sincerely, Karel.