[microtonal]

Even worse was illegal software. There were 720KB (Double Density) and 1440KB (High Density) 3.5" diskettes (amongst other sizes). The disk drive would detect the difference by an extra hole in the disk.

People would buy cheaper double density disks, drill a hole in it, so that the same diskette could be used as a 1440KB disk. Of course, they were of a far lower quality, and 'arj' (which was popular at the time) would often fail after the n-th disk.

Edit: heh, there is even a reference to drilling holes on the Apple website ;): http://support.apple.com/kb/TA39910

[acegopher]

I used an Xacto knife to create an extra notch in Commodore 64 5.25" disks back in the day so that I could take the single-sided disks and make them double-sided.

I would take one disk flipped over the other, mark the notch with a permanent marker, then cut out the outline. Most disks, like Elephant Memory, would work fine. You just flipped the disk over and inserted back into the 1541 to read the reverse side.

[nasalgoat]

I had a special square cutter tool specifically designed for this purpose. Just slot the disk in the tool, punch, done.

It helped when you were putting out hundreds of disks of pirated games on a regular basis.

[Luc]

I had a little switch to bypass the optical notch-detector on my 1541 drive.

I still think the single-sided disks were from the same production line as the double sided ones, and it was all market segmentation.

[honestcoyote]

I did the same. And disks were a bit expensive to a kid like me, so I'd even do the cut on various game disks I had, since many of them were single side only, and it was like getting a free disk.

[wayne_h]

"... flipped the disk over..."

They called them flippy disks...

[stuff4ben]

standard paper hole punch worked too, given enough hand strength :)

[bentcorner]

Haha, yeah, there was this thing that was advertised as a "disk doubler", and all it did was drill a hole through your 3.5 single density disk. In retrospect it was quite the ingenious scam.

I'm guessing that 3.5 disks were binned, so maybe you could get away with it once in awhile? Of course, the only way you could find out was to actually lose data...

[mtdewcmu]

Later on in the 90s, AOL started sending 3.5" disks in the mail, totally free. How convenient was that?