Gold Rush Copy Protection Problem - The Sierra Help Pages

Gold Rush! Copy Protection Problem

The way Gold Rush is cracked is very messy, but probably the only simple way without reverse engineering the whole AGI system.

Perhaps most of you will know, Gold Rush and AGI games in general use DIR files as an index to all the games resources stored in the VOL-files. So in this case the file GRDIR contains all the locations of the logics (scripts), views, pictures and sound resources. Example:

Resource Vol Location
LOGIC.000 1 0x000FE
LOGIC.001 1 0x012FE
LOGIC.002 1 0x033ED
PIC .100 2 0x05423
etc.

The only thing that has been done, to crack Gold Rush, is that the DIR file has been modified so that the location of the original script which called the copy-protection (logic 129) has been changed/reindexed to the location of the "intro script" (logic 73, screen after passing the copy protection). So the entries of logic 73 & 129 are pointing to the same piece of script code, the "intro script". Therefore, when the game would initialize the copy protection, logic 129 is loaded but now it ends up at the intro sequence instead.

Clever, yes; messy, yes.

Actually, if the script did only call the copy protection, there wouldn't be any problem. But among starting the copy protection sequence, the script (logic 129) also contains some sort of speed regulation routine, aimed at the "fast" and "fastest" speeds. Most likely this was done to keep the clock running at normal speed while playing on a fast game speed. The routine sets a variable (166) to a certain value depending on your clock speed. This variable regulates at which speed the seconds in the game pass. However, since the crack overrides the original script, variable 166 gets zero as value while another variable (156) is waiting to get equal to the value given in variable 166, and never does because it (variable 156) starts counting at 1.

Enough of all the boring details, the solution:

While playing the game, type "BIRD BOY" to enter the debug mode.
Enter "SET VAR", enter "166" and change its value to 20 or something (1 = fastest / 255 = slowest)
Enter "SET VAR", enter "156" and change its value to 0

Unless you restart or change the speed again, the clock will work properly. Also, if you save your game, and restore it later, the clock will still work, when having used this procedure earlier.

PS: The crack also messes up the intro-screen because of the following: Normally the background picture in the intro would be loaded by logic 73, the original intro script. However, the crack, as said earlier, relocates logic 129 (the copy protection) to the location in the VOL file where logic 73 is residing. The background pictures are often linked to the room/logic number, so logic 73 would load a background picture of that same number, 73. So instead of logic 73 loading picture 73, now logic 129 loads picture 129, instead of the correct 73.

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