Time Bandit (DOS)

Time Bandit
Developer: MichTron Publisher: MicroDeal Platform: DOS Released internationally: 1988 This game has anti-piracy features.

Time Bandit is a 2D action game, where one or two players seek out artifacts found in the various time gates. It's slightly dragged out, having to visit the 16 time gates 16 times.

Anti-Piracy

Time Bandit uses a simple manual check to determine if you can run the game.

The copy protection prompt is protected against memory modifications. When the title screen appears, a quick check is made on the copy protection routine and surrounding code, putting the resulting checksum at a location in memory. This checksum is compared in to sections of the code.

The first time it is read is at the instruction found at CS:3D22. If it mismatches the expected value, it alters the properties of enemies as they spawn or are destroyed. As the enemies are spawned, some exhibit odd behavior such as their death animation having movement at full speed. Eventually, the monsters will have properties that make them invulnerable, shoot lasers, and move at maximum speed. With the spawn rate of enemies, the changes are encountered almost immediately.

The flag is also read at CS:5e55. This reaction to the changed code doesn't seem to have a noticeable gameplay effect.