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Porting Games From Binary
CowboyRobot writes "My favorite Slashdot links are those that inspire me to embark on meaningless and time-consuming quests. This is one of them. Two Canadian game developers at Digital Eclipse have a thorough explanation of how to port a game using nothing but the binary stream coming out of the cartridge. They use the TRS-80 and Phantasy Star III as examples."
It's this kind of pointless endeavour that gives geeks a bad name.
It's this kind of pointless endeavour that makes me happy to be a geek.
Some people climb mountains, other disassemble 8085 binary code.
-- "Can't sleep, clowns will eat me!"
Unless I'm missing something, this novel idea is complete garbage. Yes, sure you can disassemble the machine code, produce some C code from that and then recompile for a new target CPU but it's not going to work for the vast majority of applications.
The reason: hardware.
Even your average 80's arcade machine relies upon custom hardware for virtually everything. The main program spends most of its time simply adjusting registers to control sprites etc, and reading from hardware to detect collisions and so on. This new code you've generated for a new CPU will still expect the same supporting hardware...
Code, Hardware, stuff like that.
This methos is of genuine value for cases of applications where the source has been lost and needs alteration - for just running invaders/pacman/etc an emulator is just as good - since you have to slow things down to run at 100% original speed. The best emulators really o absolutely emulate every facet of the original CPU & hardware - the VICE C64/PET/VIC emulator runs on a 1mhz interupt, that, as I understand it, emulates all the states of the 6502 processor exactly. If you convert bin->asm->c you would still need to put hold-states in the C code to make it step at exactly that speed, cycle for cycle. Where this method would be better than MAME/VICE style emulation is when you need to patch the code- to upgrade it, fix bugs etc. This applies more to non-game type code where old (and failing) hardware/software needs to be migrated to new hardware, maybe with minor code changes.. And if you are not tied to executing at a set pace, then bin->asm->c is a really cool thing to have.
"You lied to me! There is a Swansea!"