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Routines |
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Copied to 23424 by Copy_Loader. After the game has been loaded to 24192 this moves it down and decrypts it from the top with RRD, then starts the game at StartGame.
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Set up the stack and move the game down into place.
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| Decrypt_Game | 24622 | LD SP,65024 | Set the stack pointer to 65024. | |
| 24625 | DI | Disable interrupts. | ||
| 24626 | CALL 64512 | Call 64512 to move the game down to 23680. | ||
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Decrypt every byte from 64000 down to 23553.
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| 24629 | LD HL,64000 | Set the start address in HL to 64000. | ||
| 24632 | XOR A | Clear the nibble carried between bytes in A. | ||
| 24633 | LD BC,40448 | Set the byte count in BC to 40448. | ||
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Start rotating each byte through A to decrypt it.
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| Decrypt_Game_Loop | 24636 | RRD | Rotate the nibbles of the current byte through A. | |
| 24638 | DEC HL | Move down to the previous byte. | ||
| 24639 | DEC C | Decrease the low byte of the counter by one and loop back to Decrypt_Game_Loop until none remain. | ||
| 24640 | JR NZ,Decrypt_Game_Loop | |||
| 24642 | DJNZ Decrypt_Game_Loop | Decrease the high byte of the counter by one and loop back to Decrypt_Game_Loop until every byte has been decrypted. | ||
| 24644 | JP 23680 | Jump to StartGame. | ||
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