Protection experts out there?

NOB · 12 September 2005, 18:20

I have read that in the early Amiga day´s games have been protected by using track -1.
Is this true? And which games are these?

Codetapper · 12 September 2005, 23:12

I have never heard of this and never seen any game that attempts this. As far as I'm aware you cannot step the heads further back than track 0. You can however step the heads out past track 80, towards track 83 or so. Some versions of XCopy claimed to go to track 85 or something, but I don't see the point since no games ever went that high as not all Amiga drives would go that far.

The only game I can think off at the moment is Stardust disk 2 which uses up to cylinder 82 so 6 extra tracks than a normal disk.

jmmijo · 12 September 2005, 23:58

Just a thought here, wouldn't a -1 mean something like bump the heads against the mechanical end stop ?!?

I seem to recall you could send a command to the old CBM DOS drives to do this but I can't recall if you could do the same thing with Amiga DOS or not

Codetapper · 13 September 2005, 04:43

The Amiga floppy disk controller does not have any track numbering. All you can do is tell the controller to step one track forward, step one track back, and read/write data. There is a status bit which tells you if the controller is on track 0.

Track 0 on a disk is always around the outside of the disk. I am pretty sure that track 0 is the outer limit and it simply will not go any further out - probably a hunk of metal stops it!

NOB · 13 September 2005, 10:53

Quote:

Originally Posted by Codetapper

The only game I can think off at the moment is Stardust disk 2 which uses up to cylinder 82 so 6 extra tracks than a normal disk.

Thanks for your infos, Codetapper!

jmmijo · 13 September 2005, 17:38

Quote:

Originally Posted by Codetapper

The Amiga floppy disk controller does not have any track numbering. All you can do is tell the controller to step one track forward, step one track back, and read/write data. There is a status bit which tells you if the controller is on track 0.

Track 0 on a disk is always around the outside of the disk. I am pretty sure that track 0 is the outer limit and it simply will not go any further out - probably a hunk of metal stops it!

Yeah, just like the old 1541/71 drives, each 3.5" floppy drive has a mechanical end stop too

BTW - thanks for the info on this one Codetapper.

12 September 2005, 18:20	#1
NOB Zone Friend Join Date: Aug 2005 Location: Germany Age: 52 Posts: 424	Protection experts out there? I have read that in the early Amiga day´s games have been protected by using track -1. Is this true? And which games are these?

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12 September 2005, 23:12	#2
Codetapper 2 contact me: email only! Join Date: May 2001 Location: Auckland / New Zealand Posts: 3,182	I have never heard of this and never seen any game that attempts this. As far as I'm aware you cannot step the heads further back than track 0. You can however step the heads out past track 80, towards track 83 or so. Some versions of XCopy claimed to go to track 85 or something, but I don't see the point since no games ever went that high as not all Amiga drives would go that far. The only game I can think off at the moment is Stardust disk 2 which uses up to cylinder 82 so 6 extra tracks than a normal disk.

12 September 2005, 23:58	#3
jmmijo Junior Member Join Date: Jan 2002 Location: PDX Age: 62 Posts: 2,395	Just a thought here, wouldn't a -1 mean something like bump the heads against the mechanical end stop ?!? I seem to recall you could send a command to the old CBM DOS drives to do this but I can't recall if you could do the same thing with Amiga DOS or not

13 September 2005, 04:43	#4
Codetapper 2 contact me: email only! Join Date: May 2001 Location: Auckland / New Zealand Posts: 3,182	The Amiga floppy disk controller does not have any track numbering. All you can do is tell the controller to step one track forward, step one track back, and read/write data. There is a status bit which tells you if the controller is on track 0. Track 0 on a disk is always around the outside of the disk. I am pretty sure that track 0 is the outer limit and it simply will not go any further out - probably a hunk of metal stops it!

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