/vr/ - Retro Games

>>2625289
I think the SNES is technically a more interesting machine. The graphics are without question better, and while I've come to respect the Genesis's YM2612 as an iconic instrument that's bad ass in the right hands, I prefer the SNES's S-DSP ability to mimic a wider range of sounds, even if interpolation can make samples muddy. Also I am much more familiar with the SNES library and enjoy on hacking some of my favorite video games of yesteryear. Don't get me wrong though, I love the Genesis. I'm just not interested in developing for it.

>>2625415
There is no real mode like in the x86 in the 65816 architecture. However there is a concept called banks which has some similarities.

The 24-bit address space 65816 is fully backwards compatible with the 16-bit address space 6502. To reconcile the two designs, a bank strategy had to be employed to divide the address space up into 256 16-bit banks. The primary limitation of banks is that the Program Counter (PC, the register that keeps track of where in the program you are) wraps in a bank when executing code, thus limiting the maximum size of a program to 65536 bytes without using jumps or subroutine instructions that alter the top 8 bits of the PC. If a particular section of code exceeds this limit, you need to somewhere split up your code into two banks, and use 24-bit addressing modes to jump between the two where necessary.

This bank strategy isn't as limiting as you would think, as it's pretty easy to split programs up, and a single function will never be a full bank long if you code in any sane manner. Furthermore indexing addressing modes _aren't_ affected by bank wrapping effects. In C notation, $00FFFF[1] would access $010000, not wrap to $00FFFF. Of course your index registers are only 16-bits, so a single array can't be larger without splitting it up.

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>>2624567
I've hacked a lot on Super Metroid. I discovered a room buried deep in the ROM with no door pointers referencing it (all other unused rooms _do_ have pointers). Found a dev map ages ago and much to my surprise the secret room was there, being the only change from the final design. I don't know if anyone else knows about it.

Check out the map. It's the room boxed in with red. In the final release it's the Lower Norfair room with the Chozo statue that drains acid right before Golden Torizo. The cut version is a narrow steep slope with thick columns and the Chozo is inaccessible (or not there, I can't remember).

I love hacking because you never know what dummied out treasure you'll find.