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Old 02-12-2021, 10:56 AM   #1
Neville
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Default A small introduction to DOS games deprotectors

Because the topic was mentioned on another board some time ago, today I've decided to speak about those DOS programs that promised to get rid of those pesky DOS protection schemes. You know, stuff like "Insert the original disk", "Before we continue, check out the second sentence in the page 25 of your manual" or, even worse, "use the codewheel to find out the following data".

These days you can see all sorts of initiatives regarding these protections. Some people prefer to leave the software unaltered and even preserve their protections (some were very sophisticated, such as the codewheels included with the first Monkey Island games). Other people like me prefer to get rid of the protections and enjoy the games as flawlessly as possible.

Anyway, since I end up testing many DOS games I've reserved some space on my DOSBox installation to utilities such as Neverlock or Locksmith, and I have to admit I like them much more now than in the old days. Back then it was too common to have a version of the game that was not supported, especially if it was translated into something different than English. Nowadays, it is much easier to locate an especific version of a game.

Quote:
[These programs] are essentially databases with data such as "in the file GAME.EXE, offset 0x3471, change bytes EB 07 to 90 90".

Or, best case scenario, "look for bytes 84 01 74 0d and change them for 84 01 eb 0d". This has better chances of working, because it ignores offset.

You can still run into trouble if your version of GAME.EXE differs from the original (different language, different version, already tampered by crackers, etc.).

They work like an antivirus programs (signatures, not heuristics), but instead of looking for virus related byte strings, they look for protection related strings. They're like a COVID test!
So without further ado I'm going to list and review a few of these programs.


1) CrackAid v3.39 (1993)



Developed by some Rawhide from the Humble Guys, who don't seem like a soccer team to me. Supports 300 games, mostly from the early DOS gaming era.


2) Crock v2.32 (1994)

By Firebug y Eryx, who probably waved the skull and crossbones flag. One of the few programs that attempts to unprotect the floppy version of Strike Commander, a late DOS game that included several different protections. It doesn't remove all its protections, though.




3) Locksmith v1.31 (1994)





By REM Software, this one looks like comercial software that ended up being ilegally distributed.

This is one of the most popular programs of their type, and supports around 750 games, which is saying something. It also mentions which protection can remove, something very useful because some games have more than one type of protection, such as key disk + manual lookup.


4) The Patcher v6.5 (1995)

By Michael Caldwell. Since the author doesn't hide his name this was likely comercial or freeware software. It can unprotect around 200 games.




5) Universal NeverLock '96 (1996)





Another comercial program that ended up being pirated. It looks like a more accomplished program than the previous ones. It divides its library in two collections, the "classic games" (around 280 games) and the "modern" (with another 350 games).

On the other hand, it doesn't work exactly like the other programs on this list. Instead of patching the original program, it loads a TSR program before or instead the game executable. It also shows a nag screen with advertising.




As I said before, using this programs now has its pros and cons. Most of them create a backup of any program they patch, so it's not like we are in serious danger if we use them. It's more like nobody can warrant that these cracks work or not. Some of them are great -I recently removed the protection from the floppy versions of Star Wars: X-Wing and TIE Fighter without a hitch- but others don't work, render the game unusable or don't remove all the protections.

Under DOSBox the patched games can give us some trouble, too. If a patched game won't work under DOSBox usually the loadfix option can solve the issue.

And finally, there are many other programs like these than listed here. Nerdy Pleasures has a great article ion others and also offers a deeper explanation on how these programs work.

This is an English version of a message I posted elsewhere. Since then it has received a few answers, and also some other people offered valuable advice on the matter. Here it is:

1) The floppy version of "Strike Commander", my particular white whale, can be FULLY unprotected by the program Unprotect Professional v5.0 (1995).

2) Have a different version of a game you want unprotected? OK, try this: Patch the English supported version of the game with one of these utilities. Then use a byte comparer such as UltraCompare to see which strings were changed, and change them in your version of the game with an Hex Editor.

Last edited by Neville; 07-12-2021 at 06:10 PM.
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Old 09-12-2021, 04:45 AM   #2
DrWho42
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thanks for the intro!
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