Trying to recover 67's prerecorded magnetic cards

[[kby]]

Yes, these are the things I’m thinking of. Apple laptops (maybe others) generally sleep when the lid is closed with the laptop on. This is accomplished with a Hall effect sensor in the keyboard/trackpad area and a magnet in the lid. The same is true for iPad covers that put the tablet to sleep. It’s very hard to be always aware of this. The “smart connector on iPad Pros has magnets. In recent model iPad pros the attachment of the Apple Pencil stylus to the tablet for inductive charging is uses a magnet. I had previous cards erased by having them close to a case that used magnets. Placing the tablet on top of the Kangaroo case of a -65 with cards in the front pocket can be enough yo render them unreadable. Remember, you don’t have to totally erase the card to make it unreadable; just done of it.

That still doesn’t address why the cards can’t be rewritten. That’s more likely mechanical wear or something else that caused oxide to flake off. Again, doesn’t have to be everywhere.-kby

(08-22-2021 01:59 PM)vassilisprevelakis Wrote:  Actually there are many more permanent magnets around nowadays then in the 70s and 80s. Take, for example, the cover of my tablet, which is magnetically attached to the tablet. I frequently see paper-clicks attached to the cover. Even the power plug of my Mac is magnetic.

So if you have magnetic cards lying around, you have to be aware of all these magnetic traps and keep your cards safely tucked away. Keeping them in a box (even non-metal) sounds like the best advice. You keep them there and only take them out when you need them and then put them back.

Vassilis

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