I've just recently switched from a TI-84 to a TI-89 and I find that it's taking a while to get used to the different keyboard format. My question is, would it be possible to to change where the keys are mapped? Such as pressing the green Diamond button on the TI-89 would actually be pressing the ALPHA button.

On https://www.ticalc.org/pub/89/asm/programs/ there is a program called "Sim beta 1c : TI89 <-> TI92+/V200 emulation" that looks like it can do it, but it's says it's only for programs so I'm not really sure what it means for that and I'm really sure how I'd get it to work

Any help would be appreciated!

After two weeks I still haven't been able to work it out but I did learn that it's possible to try to hook the ngetchx() function or tigcclib's _rowread(). Would anyone please be able to guide me on how to hook or overwrite these two functions across the whole calculator?

It is possible to remap keys. That program is merely an emulator for other programs, it has nothing to do with the calculator itself.

You may want to look into how to install a TSR, and execute keypresses when you receive events such as CM_KEYPRESS. I would suggest taking a look at how XtraKeys v.3.00 does it here: https://www.tigen.org/kevin.kofler/ti89prog.htm