Author Topic: Immunized Disks  (Read 4820 times)

Offline Diaboł

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Immunized Disks
« on: February 03, 2011, 07:52:59 PM »
I review the Atari ST Demos [ST] DAT and I'm a little confused. There's a few antivirus programs for ST. You can immunize a disk to protect the software against viruses. There's an information about that in many set names. It takes one of the following forms:

  • [a Floppyshop anti-virus]
  • [m Floppyshop anti-virus]
  • [Floppyshop anti-virus]

According to TNC only the last one seems to be correct but I'd like to ask just in case.



Offline TKaos

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Re: Immunized Disks
« Reply #1 on: February 03, 2011, 08:43:44 PM »
Isn't "[m Floppyshop anti-virus]" the best option to use?
The disk was modified with an antivir software.

Offline Diaboł

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Re: Immunized Disks
« Reply #2 on: February 04, 2011, 05:50:16 AM »
Quote
"Modified – [m]
General hack. It's used when someone modified the game like changing the color of the main character, adding support for other controls like lightgun."

Non of the files on a floppy disk are being changed while you immunize disk. Looks like it's a boot sector protection.

Offline Aral

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Re: Immunized Disks
« Reply #3 on: February 04, 2011, 08:57:26 AM »
I agree Tkaos.  Heres one such example on the amiga...

Barbarian II (1991)(Psygnosis)(M4)(Disk 3 of 4)[cr SR][m disk-validator]

Offline Diaboł

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Re: Immunized Disks
« Reply #4 on: February 07, 2011, 01:44:55 PM »
What if I have 4 files:

Name (19xx)(publisher).zip
Name (19xx)(publisher)[a].zip
Name (19xx)(publisher).zip
Name (19xx)(publisher).zip

Last two have different crc/sha/md5, there's no obvious difference between them and both were modified the same way? Can I use extra [a]? It would be like:

Name (19xx)(publisher).zip
Name (19xx)(publisher)[a].zip
Name (19xx)(publisher)[m modification].zip
Name (19xx)(publisher)[m modification][a].zip


edit:

or:

Name (19xx)(publisher).zip
Name (19xx)(publisher)[a].zip
Name (19xx)(publisher)[m modification].zip
Name (19xx)(publisher)[m modification][a2].zip
« Last Edit: February 07, 2011, 01:50:56 PM by Diaboł »

Offline PandMonium

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Re: Immunized Disks
« Reply #5 on: February 07, 2011, 02:11:19 PM »
Correct. If you couldn't figure it out why the 2 were different at all you would use just [a], (your 1st example).

Offline Diaboł

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Re: Immunized Disks
« Reply #6 on: February 07, 2011, 02:12:25 PM »
Thanks!

Offline TKaos

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Re: Immunized Disks
« Reply #7 on: February 07, 2011, 04:25:33 PM »
I think it should be more like this:
Name (19xx)(publisher).zip
Name (19xx)(publisher)[a].zip
Name (19xx)(publisher)[m modification].zip
Name (19xx)(publisher)[m2 modification].zip

We're using numbers already for alternative files and bad dumps & hacks and as far as I know the numbering can be done with any flag in brackets except [!].

Offline Diaboł

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Re: Immunized Disks
« Reply #8 on: February 07, 2011, 04:42:09 PM »
Could be strange to see:

Name (19xx)(publisher)[m Floppyshop anti-virus].zip
Name (19xx)(publisher)[m2 Floppyshop anti-virus].zip

since the modification is exactly the same.

Offline PandMonium

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Re: Immunized Disks
« Reply #9 on: February 07, 2011, 05:53:46 PM »
TKaos is probably right here, sorry. It actually depends on the images and can be really hard to figure.

Explaining with an example:
Case 1:
Given a single, original disk. Imagine it was not write protected (or in case of dumps, the emulator altered the rom). You and me both have the exact same disk (or image). If we dump it *now*, we get both the same hashes as the disks are equal. However we both use them and they get modified - say, overwriting the highscore. Our once exactly equal disks were now modified, different from an untouched one. Dumping both would result in different files/hashes, for "Name (19xx)(publisher)[m highscore]", so one of them should have "[m2]", signaling a different modification.

Case 2:
This time we have 2 disks, they are the same game but with a slight difference, yours was released with harder enemies. Dumping both unmodified sets will now result in 2 different dumps "Name (19xx)(publisher)" and probably "Name (19xx)(publisher)[a harder]". This time, they were different from the start, even if they suffer similar modifications, say they were, again, played and scores overwritten. In my logic, they would now be "Name (19xx)(publisher)[m highscore]" and "Name (19xx)(publisher)[m highscore][a harder]", because, each of them was the first modified version of their scores. Got it?

The nice part about all this is it is ALL theoretical, in a perfect world it should work like that. The problem is that you're starting with the dumps already and many times (almost always?) you can't figure out what happened with such details.

Offline TKaos

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Re: Immunized Disks
« Reply #10 on: February 07, 2011, 07:10:41 PM »
And now I start to think of what happens if I have 1 crack but 2 different CRCs...also [cr Black Bag] & [cr2 Black Bag]? :)
If so we'll have a new goal. :P

Offline PandMonium

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Re: Immunized Disks
« Reply #11 on: February 08, 2011, 12:56:13 AM »
It can mean a lot of things, excluding the possibility of sets being different from the start because then they would have a different name and t different hashes, applying the same crack on both will result in different files (and assuming you could identify this properly and the crack would work on both :D).
If they were originally the same set, that was cracked (and all the rest is equal), a different file (hash) might mean one is cracked and the later was probably a fix for a bad crack? It can also mean the game got modified by some other still unknown reason (m flag missing?).

Anyway and even in these cases, dump flags support counters, in this case you have the group name and it is probably ultra *rare* to have the same exact file cracked by the same group and resulting in 2 images. If you leave out the group name or descriptors you will see that this actually happens much more frequently than we would like.

However i'm sure 99% of these cases are just lacking information that could improve and differentiate setnames, see the 1000 hacks of mario with [h2] to [h999999] (that could be properly renamed with a bit more efford) or the tons of [a] to [a20000] in some sets, where i'm sure most are actually [m ] or [ h] and the remaining, if alternate should have a descriptor.