D7314@uwavm (Patrick Ryan) (02/28/88)
Write protection can be gotten around by pure software. Copy 2+ (bit copy) version 3.xx would write to a copy-protected disk, but I don't know how they managed it... I'll check into it and see what I can see.
neighbor@csd4.milw.wisc.edu (Jeffrey Alan Ding) (03/02/88)
In article <8802280319.aa05119@SMOKE.BRL.ARPA> D7314@uwavm (Patrick Ryan) writes: >Write protection can be gotten around by pure software. Copy 2+ (bit copy) >version 3.xx would write to a copy-protected disk, but I don't know how they >managed it... I'll check into it and see what I can see. You are ABSOLUTELY WRONG when you say that! The hardware in the disk drive will not write to a disk when the write protect switch senses write protection. If your program does not bother to check write protection, the program will go through all the moves and it will appear that you wrote to the disk. But if you look at the disk, nothing will have changed. Write protection is hardware (at least on the Apple computer), not software. neighbor@csd4.milw.wisc.edu
GZT.EWW@OZ.AI.MIT.EDU (Wes Williams) (03/05/88)
Brent writes>How else could the original suddenly stop working
>except to be written to?
Good question! I have not been a cracker as I needed my cpu time working
the systems or doing other things. I do think that a good general
description of the basic types of disk protection is worthwhile.
I would like some indication as to the methods employed for the following
types of copy protection.
1. How does the " copy all you want until the disk has been booted
one time" work?
2. How does the "copy from the original but not from a copy" work?
3. How does the "lotus 123 ((I know, this is a different animal))
remove a hidden file from the disk on copy" work?
4. I have seen protected software self destruct an original when
a copy program is run to make a backup. As these originals are write
protected, how is the protected software screwing things up?
I don't need the specifics, all those track and sector bits of info
boggle my mind and I mumble for a week. I'd just like to have a feel
for it.
\|/es \|/illiams
gzt.eww@oz.mit.edu@xx.lcs.mit.edu.arpa
-------neighbor@csd4.milw.wisc.edu (Jeffrey Alan Ding) (03/06/88)
In article <12379906200.78.GZT.EWW@OZ.AI.MIT.EDU> GZT.EWW@OZ.AI.MIT.EDU (Wes Williams) writes: >Brent writes>How else could the original suddenly stop working > >except to be written to? > >Good question! I have not been a cracker as I needed my cpu time working >the systems or doing other things. I do think that a good general >description of the basic types of disk protection is worthwhile. > >I would like some indication as to the methods employed for the following >types of copy protection. > 1. How does the " copy all you want until the disk has been booted >one time" work? Do you mean here that you can copy a disk as much as you want but when you boot it you can't copy it anymore? This makes no real sense. If the disk is write protected, the disk cannnot be changed in any way. See answer to #4 below for more details. > 2. How does the "copy from the original but not from a copy" work? In this case... The copy of the program is already munged. It most likely isn't an exact bit per bit copy of the original but close enough to work. When it is used to make another copy, the new copy gets degraded even more, enough so that it won't work. Sort of like making a copy of a copy of a copy of a page in a copy machine. The farther down you go, the less acurate the copy becomes compared to the original. > 3. How does the "lotus 123 ((I know, this is a different animal)) >remove a hidden file from the disk on copy" work? I'm not sure what you mean here. Lotus checks for something on the key disk that doesn't copy with the standard MS-DOS copy program. But copyIIpc can easily copy it. > 4. I have seen protected software self destruct an original when >a copy program is run to make a backup. As these originals are write >protected, how is the protected software screwing things up? In my opinion it is not the copy program that screws up the protected software. Some protection schemes are very flaky. So flaky that it takes several times to read the same information from the disk without making a soft error. Soft errors are where you read it once and it is ok, the second time it gives an error, and the third time it is ok again. Soft errors are caused from bad media on a disk or poorly designed disk I/O routines. After the disk gets read a few times the soft errors could develop into permanent errors on the disk. Some copy programs (especially bit copy programs) move the disk heads in a fashion that was not intended. This could cause extra wear on the disk, possibly depositing dirt on the media from the drive head. If this happens, soft errors could easily turn into permanent errors. I have never seem a ligitimate case of where a copy program screwed up a write protected program in the process of copying. It was always some other problem like write protect tab falls off and wrong disk inserted. Or with one drive systems, the original was put in the disk drive to fast and the disk got bent or the media damaged. These opinions are exclusively mine and mine alone! neighbor@csd4.milw.wisc.edu