The original very rare super game Grogs Revenge, by Coleco Canada, was release with a nasty bug. When you use the warp codes listed in the manual for mountain 1, and you warp up to Level E, and went into any cave, the screen went black, and the game froze. Well Thanks to Oscar Toledo, that bug has been repaired using the following modification...
From Oscar Toledo,
I've analyzed the game and I've trimmed down the bug.
1. The bug happens when entering any cave of level E of mountain 1.
2. The game has an internal buffer of 64 bytes.
3. The buffer is filled with X+Y+Y elements (shells, stalactites and
4. Coleco programmers made a mistake, the total number of elements was
57+20+20 = 97, this doesn't fit in the buffer of 64 bytes.
5. This is the only level where they made the mistake.
6. I've patched it to 16+20+20 = 56 elements.
Find annex the patched DDP file (byte $5374 in file changes to $10,
this is $b074 in ADAM memory)
BTW, the passwords for mountain 1: 2,2-3,3-4,4-5,5-6,6
For mountain 2: 2,2-2,3-4,4-4,5-6,2-7,8
For mountain 3: 4,2-6,6-7,1-2,3
Now. After fixing that bug, another one popped up where you warped past level E, the game would go into oblivion, and crash. Oscar has fixed that problem too, with the following modification...
>>> For block patch this is block #28, sector #3, blk: 93 (it contains $06, patch to
>>> $05) and blk: 120 (it contains $06, patch to $04)
People who have this game, sealed or not, are going to need these modifications to use the game. So make note of these changes. Any questions, let me Know. I'm on atariage as Klasko54
Edited by klasko54, Thu Oct 1, 2015 9:12 PM.