Sabotage (On-Line Systems, 1981)

[toinet]

#995 - Sabotage by Mark Allen, one of the first filecrack I ever played on the Apple II. Disk image by Stephane Racle.

Disk structure
The disk is a standard DOS 3.2 (13-sec disk). It can be read, copied. It shows no sign of on-disk protection.

Protection type
But there is one. If you copy the disk (DOS 3.2 to DOS 3.2 or to DOS 3.3), the HELLO file is run, it loads the BANNER file and BRUNS the SABOTAGE file that hangs. When you look at the loading address of SABOTAGE (the game), it is at $1D00. That address is one largely used by On-Line Systems / Sierra to put their protection scheme: a nibble check thing.

How to copy
We'll put the file onto a standard DOS 3.3 slave diskette. Perform the following operations:
- Insert a DOS 3.3 Master disk in drive 1 and boot it
- Insert a blank disk in drive 2 and type INIT HELLO,D2
- RUN CONVERT13,D1
- Insert the Sabotage disk in drive 1
- Perform a copy (wildcard is '=') of the 4 files from S6,D1 to S6,D2
You're done.

How to normalize
Now, boot my copy disk and launch Disk Fixer, we still have the DOS 3.3 version of Sabotage in drive 2. Now put it in drive 1 and perform the following change:
- Press D to display the catalog, follow file SABOTAGE
- At offset $50: FF 1D => 1E 1D, or
- Another option: at offset $22: 60 -> EA
- Save the sector
You're done

The disk image is available at http://www.brutaldeluxe.fr/crack/

Reboot and... enjoy,
LoGo
8/2018

[toinet]

The Disk fixer view. The data to change are within '-', choose the option to crack it.

[toinet]

The first part of the code at $1D00, a funny way to play with the stack to call routines (and the protection check at $1E00)

[toinet]

13/Jul/2019 - Allen Greene on the Apple II Enthusiasts group on Facebook found out that there were a deleted file on the original disk of Sabotage: SOCCER.

I dug the original disk image, made another DOS 3.2 to DOS 3.3 conversion with Advanced Demuffin 1.4. Then, I undeleted the SOCCER binary file. It loads at $4000 and was intact.

Protection type
Check of nibbles on T0/S0.

How to crack
Follow file SOCCER, at sector offset $E, at byte offset $3B, change 20 00 51 with 2C 00 51.

Note that the game runs on 6502 machines only.

How to use
Boot the disk at http://www.brutaldeluxe.fr/crack/ (On-Line Systems - Sabotage with Soccer - cracked.dsk). At the DOS 3.3 prompt, press CTRL-C, then BRUN SOCCER.

Reboot and... enjoy,
LoGo
7/2019