Emulator Cheats

Hello Pugsy,

I have been trying to make a cheat for the Ultimate Mortal Kombat 3 rev 1.2 (umk3.zip Mame Arcade Rom) Galaga mini game so that I can lock the 3 lives, effectively giving myself infinite lives for this mini game. I used the Mame Debugger Cheat search and managed to find the following promising addresses:

>cheatlist
Address=085C7480 Start=03 Current=01
Address=085C7488 Start=03 Current=01
Address=085C7490 Start=03 Current=01
Address=085C7498 Start=03 Current=01
Address=085C74A0 Start=03 Current=01
Address=085C74A8 Start=03 Current=01
Address=085C74B0 Start=03 Current=01
Address=085C74B8 Start=03 Current=01

However, when I opened the memory window (Ctrl + M) and went to those addresses, I do not see any values at all which corresponds to what was found while stepping through the debugger at various stages during the gameplay:

085C7400 0000 0000 0000 0000 0000 0000 0000 0000 ................
085C7480 0000 0000 0000 0000 0000 0000 0000 0000 ................
085C7500 0000 0000 0000 0000 0000 0000 0000 0000 ................
085C7580 0000 0000 0000 0000 0000 0000 0000 0000 ................
085C7600 0000 0000 0000 0000 0000 0000 0000 0000 ................

Then I read about the Midway Wolf Unit having strange memory schemes for ROM and RAM in the Holy Cheat guide, but I am still not able to pinpoint the exact RAM region following the guide.

What I want to ask is that is there some kind of special offsets that are required to be able to calculate the real addresses in the RAM which corresponds to the maybe fake addresses seeing from the cheat search?

Thank you very much in advance and I am a great fan of all of your work over the years!

midwunit.cpp doesn't show any RAM in the 0x8000000 region either. Sure it's not just a mirror? For example, what is 0x005C7400 or 0x015C7400 etc.? PS1 games tend to so that a lot as well. A ROM cheat might be more viable if the data isn't compressed e.g. just NOP it out.

I already tried converting using the guide in Holy Cheat pdf about Midway Wolf Units but doesn't matter which way I do the conversion, the end resulting ROM address goes outside of the game's memory range. Anyway I solved it by using Cheat Engine searching for 2 byte value and freezing the found values.

Midway games memory can be odd for sure

Try dividing the address found by 8...

Try :-

And as a side note, just knocked up a quick ROM Invincibility for what it's worth...

Thx so much Pugsy! May I ask how you arrived at 59F38 as the address? I tried dividing the value I had by 8 as you suggested but it is not the same as the value you have gotten for the cheat?

85C7480/8 or simply 10B8E90 is the lives address - 85C7480 is the address you posted above.

59F38 is the program code address for invincibility (not what you asked for - and unrelated to infinite lives).

ah ok understood. You are a legend! Thx Pugsy once again