So with this in mind, I disassembled some of the code (using Zen) to see if I could give myself a better chance of completion. Patching memory location hexadecimal 184B with zero gives infinite lives. For those interested in the technical detail, this replaces a DEC (HL) instruction with NOP so the number of lives stored in BD96 does not decrement when you lose a life.
The number of lives is initialised at the start of the game by the number in 152F. So you can alternatively improve your progress with some extra lives if you think infinite lives is too extreme. However, be aware that patching a number higher than hexadecimal 10 into 152F causes screen corruption as there's a finite amount of space at the bottom of the screen to display the animated figures that represent your lives.
The starting cavern is initialised by the number in 1526 (hexadecimal) and the caverns are numbered consecutively from zero upwards. So patching in a higher number starts the game on a higher level and this can be great for saving you time or bypassing a level if you're completely stuck! There are 20 (decimal) different caverns and you can start in any cavern you'd like by entering a hexadecimal number between 00 and 13 in MOS. To clarify with some examples, The Cold Room is 01, The Menagerie is 02, Attack of the Mutant Telephones is 0A, and The Final Barrier is 13.
So to give yourself a fighting chance of seeing the game in its entirety and actually completing Manic Miner, the process involves initialising DOS as usual, loading the game into memory, entering MOS to patch the game, followed by G100 to start playing the game.
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Load the game into memory by typing LOAD and the name of the file (including the .COM suffix) followed by [ENTER]
Then type MOS [ENTER] to invoke the MOS prompt
For infinite lives:
Type M184B [ENTER] (and the screen should show 35)
Type 00 [ENTER] (to overwrite the 35 with zeros)
Type . [ENTER] (entering a full stop will exit the modify command)
Alternatively (or additionally), to increase your number of lives:
Type M152F [ENTER]
Type a hexadecimal number between 03 and 10 [ENTER]
Type . [ENTER]
Optionally, to start in a different cavern:
Type M1526 [ENTER]
Type a hexadecimal number between 01 and 13 [ENTER]
Type . [ENTER]
When you've finished:
Type G100 [ENTER] (to start the game)
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It's probably worth mentioning that the game code includes ASCII strings for "INFINITE LIVES" and "CHOOSE CAVERNS" so there may already be an inbuilt cheat in the game. Cameron Else, who programmed this great Einstein Manic Miner version, included a cheat in his port of Jet Set Willy for the MSX where you pause the game and type in a word to enable the cheat. So Cameron may possibly have implemented something similar on the Einstein version of Manic Miner. Do follow up on this post if you find an inbuilt cheat!
I am quite surprised that there seems to be very little information in circulation about cheat codes for the Einstein. Is anyone aware of any cheats for Einstein games?
Enjoy!
Richard
