Do you want to check whether a certain variable is odd or even? This is fairly easy in Assembly: simply check if the lowest bit is odd or even, and you know that the entire byte is or isn’t as well. There are a few ways to code this though. In this post, I’ll briefly go through all methods, explain why they work and tell you my favorite way to do it.
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Assembly 101: The status register
The 6502 registers youre probably most familiar with, are the accumulator and the X- and Y-registers. There are three more registers though, which you may not access directly through code, but are at least as important as the former three. In this post, I’ll explain all about the Status register, and how this works with other instructions. This is a somewhat longer post, so buckle up and dive in!
Assembly 101: Branches and compares
The Assembly 101 series touches upon the various isntructions that the NES’ 6502 assembler uses. These instructions make up the program language that is Assembly. In this post, we take a look at the various types of branches that exist within Assembly.