[TacticalCoder]

Hence the cracking scene: home users would get pirated version of the games, with the copy protection removed from the code.

P.S: if I'm not mistaken in some cases original, legit, disks were physically damaged on purpose (for example with a hole being physically punched at a precise location) and then the copy-protection would try to write something at that spot and re-read it. If the write/re-read succeeded, they knew the floppy was good and hence they knew it couldn't be an original disk.

[deaddodo]

That doesn't make sense, no? Most of these disks had their read-write tab blocked and so the floppy drive would just operate in read-only mode anyways.

[TacticalCoder]

> That doesn't make sense, no? Most of these disks had their read-write tab blocked and so the floppy drive would just operate in read-only mode anyways.

You are right that that doesn't make sense so I may be remembering incorrectly.

I'm nearly sure the disk physically had holes, on purpose, though. So maybe the copy-protection was simply trying a regular read, expecting it to fail... And if it didn't throw an error, then it'd know it was a copy.

[amiga386]

I can give you an example of someone claiming there were holes in the disk, Jon Burton, but they're a goddamn liar: https://www.youtube.com/watch?v=Qaq9vlfoGnA

I have the original release of Leander. There are no holes in the disks. The code on the disk doesn't write anything besides hiscores. There is a protection routine exactly where he says there is, however what it does is check for a long track. It waits for the index pin, reads lots of data from the track, then looks to find two sync marks in the data it read, and they're at least a certain distance away from each other. No lasers, no holes, no writing. Standard long track protection. Here's the whole routine: https://pastebin.com/c1wnaJBP

Here's a page that more accurately describes floppy disk protection methods (and also explains what a long track is): https://diskpreservation.com/dp.php?pg=protection

[rasz]

>It waits for the index pin

you mean index hole?

>no holes

https://s3.amazonaws.com/com.c64os.resources/weblog/howdoes1...

so maybe no laser holes, but there IS a hole :-)

[deaddodo]

If you watch the original video, the person OP is talking about referred to an arbitrary hole that they added themselves/the disk producers added. The index hole is a normal feature of floppy disks that are "flippy" (usable on both sides).

In addition, OP wasn't talking about the index hole, which was only used on a few platforms. They're referring to the index PIN, which is one of the signal wires that comes out of the floppy device.

So you're doubly wrong, in this case.

[rasz]

How does the floppy infer when to signal on the index PIN?

[Semaphor]

I remember downloading some kind of commercial digital forensic software that, came with cracking instructions: A PDF or image with measurements for where to drill a hole into your disk and at what size :D Never tried it, so I don’t know if it would have worked, but I’ll always remember it.