How Do I Subtract from a Register Using Gecko Codetypes?

Gecko Codetype 86 allows you to do several operations to Gecko Registers. I can add, multiply, xor, or, and, rotate left and right, and do float add or float multiply. However, it's conveniently missing the subtract operation. Is there some method I'm unaware of that can be used to subtract from Gecko Registers, whether or not it's with Codetype 86? And if there are such methods, how would they be done with both typical hexadecimal values and float values?

If you can find an Hexadecimal PPC opcode chart, would there be a way to add that opcode into the gecko code? I'm just seeing if there'd be a way to fuck around on it, try certain things, etc.

On the NES Game Genie, all codes were done through some sort of 6502 ASM, and even someone who doesn't code, especially in ASM, they'd still be able to make codes. I understand PPC is a lot more complex than 6502, and perhaps that is why the "gecko code" creators implemented both RAM writes, as well as PPC writes, because of the hardware workings, it seemed more acceptable that way. But there was probably just a push to get the gecko released than have every single thing thought through and of.

Going back to what I first said: Open up Gecko dotNET, search for an address with the subtract instruction, one that is preferred, and if you compare the Hex to every other instruction, you can figure out how to write an instruction with Hex in the sense that each bit of Hex corresponds to part of the instruction, its value, etc. I did this a while back but gave up on it, considering I'd never use it. I wrote it all down on paper, but probably threw it out.

Also, you could perhaps do an instruction in the unconventional way, like do all this and that to do one instruction when you can't do it by just a single instruction. There's a term for this, but I can't remember it, unfortunately.

Hopefully, you figure it out, man. Would like to see how as well.

SnB@BWH wrote:
Hopefully, you figure it out, man.   Would like to see how as well.

I ended up doing what I always do and just BS'ing it with ASM. Used a C0 Code, loaded the memory address, it's current value, and the value I wanted to subtract into registers and then used the sub instruction to finish the job.