How Do You Notch Your 5.25 Floppies?

or maybe How Do You Notch Your Pen Drives?

With one notch for each IE I replace with FireFox.

I am sure nobody knows precisely why, but there was considerable inertia in media to have a "write enable" widget.

9-track tape used a plastic ring (that came in lots of colors.) mounted in the flange of the supply reel to enable write. Most shops had a stick set up somewhere near the scratch-tape rack so the ops could play ring-toss while slowly waiting for DUMPER to run.[1]

3/4-inch videotape used a little plastic plug, invariably colored red, called a "dirt" == DRT == damned red thing which was specially designed to roll under the toe kick of an equipment rack when you had less than a minute to set up a recording you forgot was coming, and they were only going to feed it once and you were going to air it later that day.

I remember something in vaguely QIC form-factor that had a write-enable plug that reminded me of dirts, but now I can't precisely place what used them. QIC150 had an integral write-enable plug that you rotated 180 degrees to expose or cover a notch. Was it QIC24 that had losable plugs? Or maybe QIC11?

When 3.5-inch floppies showed up on the scene, they went back into the "cover the hole to write enable." , they just made the write-enable plug a permanent fixture on the media (well, except for disks that were sold for software distribution that didn't)

Footnote 1: Once I tossed a user from my shell server, and told him to meet me at a local geek gathering to receive a copy of whatever he had in his home directory at the point of his account termination. I showed up with what, to me, was the most universal and easily created backup media: A mini-reel of 1600 bpi 9-track tape (So thoughtful I was not to use 6250 ... those drives were harder to come by.) I knew it would burn his toast, but it did satisfy the terms of the contract - and kept in line with my published customer service policy. (Which was, in its entirety: I promise not to poke you in the eye with a pointy stick.)

On a single-sided drive, there's no sensor on the opposide side, so you punch a hole (if there wasn't one already) and flip the disk over to use the other side.

This was supposed to be bad for the disk, the drive, and your data (for the drive, apparently debris collected by the felt liner inside the disk could be deposited on the r/w heads) but everybody still did it.

Doesn't the notch select between HD and DD 5.25" disks and not between single-side and double-sided? I was going to vote for the last poll option and thought -- hey that's wrong!


Umm NO! The notch was only for write enable/protect. Early drives were single sided. Many floppies were double sided. Many single sided floppies were really double sided, but not certified. Use the second side at your own risk. If you notched the other edge, you could put it in a single sided drive up-side down and write the second side for free.

HD disks were jacketed the same as a normal floppy, but took stronger magnatism to write it. Other than the label, there was no way to tell a HD disk by looking at it. Using a HD floppy in a regular drive often failed. If it was formatted low density in a high density drive then sometimes you could read it in a low density drive. It depended on how much noise was between the tracks the wide low density read head picked up.

The 3 1/2 inch drives were the ones that had an extra hole to identify them as a high density floppy and moved them from 360 or 720K to the 1.44 we are used to. It's very hard to find low density 3 1/2 floppies anymore.