6502 ASM FAQ

This page is a list of frequently asked questions about 6502 ASM.


Is 6502 ASM easy to learn?

Compared to other assembly languages, yes. The 6502 microprocessor is a relatively simple processor, therefore 6502 ASM is relatively simple. Even though it is easier to learn than most assembly languages, it still requires alot of patience.

My computer isn't a 6502, what do I do?

Celebrate! You're not using an outdated microprocessor. But in all seriousness, very few people develop for a 6502-based system anymore. Instead, people develop for 6502-based emulators.

Is there a generic 6502 development environment?

Yes, and we love it much. You can find it on it's own page : the 6502 Macroassembler and Simulator. Unlike most 6502 simulators, the 6502 MAS includes an input/output screen allowing you to make simple text-based games.

Is there a generic 6502 emulator?

Not really. For programming the 6502 to be fun, it has to be hooked up to something so that it can take input and give output, say, a joystick for input and a television for output. Without these, programming a 6502 is about as fun as watching the paint dry.

Luckily, there is a 6502 emulator that has a minimum amount of extra hardware emulated as well. You can find it online at 6502asm.com.

Developing for Video Game Consoles

I've heard that if I learn 6502 ASM, I can make games for video game consoles, is this true?

Yes, to a certain extent. The Atari 2600, the Nintendo Entertainment System and the Super NES all use 6502 ASM or an extension of 6502 ASM. Learning 6502 will be your first step in developing for these video game consoles.

However, these video game consoles are not just their microprocessor. You will have to learn about the architecture of the entire video game console, which is specific to each one. 6502 ASM is just the core language they speak.

Why is 6502 assembly used for games?

Because it's fast and 6502's are, to put it bluntly, extremely slow compared to modern microprocessors. Games had to be written in ASM just to be able to get them to run as fast as they did.

Will you help me hack a ROM?

No, we will not. This is not a ROM hacking site. Commercial ROMs are against our rules. The only ROMs that are allowed are open source ROMs that come with explicit licensing information.

ASM and Machine Language

Whats the difference between 6502 ASM and Machine Language?

Not much. For example, all assembly instructions directly translate to a opcode that the 6502 can understand. The main difference is that assembly provides a bare minimum of programming functionality such as labels.

What is disassembly?

Disassembly, in a nutshell, is a process where the numerical opcodes of a binary file are examined and then replaced with the matching instruction mnemonic.

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