Comment on Dont copy
Kolanaki@pawb.social 11 months ago
I remember some brands of blank floppy disks had a notch you could slide into 1 of two positions to lock or open it for writing. Have no idea how that worked.
The drive had a sensor that detected the notch status and either allowed (or not) the write ability.
Basically the same as SD cards today, it’s just assumed that the drive will respect that switch.
Older 5.25-inch floppies you would cut a notch in a specific place, and you could use tape to cover it and make it writable again.
VHS and audio cassettes work the same way too.
For 3.5” floppy, an infrared LED and light sensor is used. If write protext slider is in the closed position, the light is blocked, and you can write to the disk. If the slider is in the open position, light passes through, and the disk is read-only. For floppies that were manufactured specifically to distribute software, they’d sometimes not have a slider at all, so you could never accidentally overwrite the disk. (At least, not without taping over the write protect hole.)
Later 3.5” floppies would have two holes, on either side of the label. One was the write protect hole, and the other identified the disk to the drive as a 1.4 MB high density disk, as opposed to the earlier 800KB disks.
Other way around. You punched the edge to make it writeable (or double-punched to write on the back side, if you were brave). Cover it to make it read-only. The 3.5" sliders were the same mechanism, open was write, closed was read-only.
Oh the double punch. That’s a deep cut there
lnxtx@feddit.nl 11 months ago
Using a tape to trick the sensor, reusing a floppy that was included with a keyboard.