How to Make Your Own Atari 2600 Game

• Step 1

  Plan out the type of game you want to create.

• Step 2

  Using Notepad (or a similar text editor) begin coding the game using 6502 Assembly language. You can save it as filename.asm.

• Step 3

  Run the code through DASM, an assembler that will take take your source code and turn it into something more recognizable by the CPU in the Atari 2600. The binary will be output as filename.bin.

• Step 4

  Load the resulting file into an Atari 2600 emulator to test it out and see if it works without any bugs.

• Step 5

  This step is optional, but if you have the proper hardware required, you can write your game to a ROM chip and load it into a cartridge to play on a real Atari 2600.

• 5
• Text editing program DASM compiler program ROM chip writer and blank ROM chips (optional)
• Text editing program
• DASM compiler program
• ROM chip writer and blank ROM chips (optional)
• The first and most overlooked step is always "plan out the type of game you want to create." The gameplay, the goals, the AI, graphics and sound--everything you do will affect something else, especially on such limited hardware. You may quickly find that having a large character sprite on screen is taking up all of your memory or CPU cycles and that it's not exactly a trivial task to go back and rewrite all of that. Keep in mind the limited color palette you'll have to deal with and even the limitations placed on sound. You aren't only dealing with glitchy, low-fi noises which you'll have to turn into music, they also take up memory and CPU cycles. You could very quickly find yourself with a slow, unplayable game if everything isn't carefully considered. As you might have quickly found out, you have to have a pretty strong stomach to deal with Assembly code. Unlike Visual Basic or C++, Assembly is a low-level language that is more suitable for talking directly to the hardware. It also takes up less space which is crucial for the environment you'll be working in. Atari 2600 games were less than 10K, on average, with most around 4K or less. 6502 Assembly is required because that's the language understood by the Atari 2600, which uses the MOS Technology 6507, a cheaper chip based on the MOS Technology 6502. It would be helpful to pick up a book on this language or use online resources. There are a lot out there. The Atari 2600 was a tricky beast to write for and a lot of it had to do with the Television Interface Adapter chip, which was the heart of the graphics and sound generation system. You should learn as much about this chip as possible and how it relates to putting graphics on the screen. As with most consoles and graphics systems today, you can access software-libraries that already deal heavily with displaying graphics on a screen, but in the old days, you had to take all of that into account and write it by hand. Good luck!
• The first and most overlooked step is always "plan out the type of game you want to create." The gameplay, the goals, the AI, graphics and sound--everything you do will affect something else, especially on such limited hardware. You may quickly find that having a large character sprite on screen is taking up all of your memory or CPU cycles and that it's not exactly a trivial task to go back and rewrite all of that. Keep in mind the limited color palette you'll have to deal with and even the limitations placed on sound. You aren't only dealing with glitchy, low-fi noises which you'll have to turn into music, they also take up memory and CPU cycles. You could very quickly find yourself with a slow, unplayable game if everything isn't carefully considered.
• As you might have quickly found out, you have to have a pretty strong stomach to deal with Assembly code. Unlike Visual Basic or C++, Assembly is a low-level language that is more suitable for talking directly to the hardware. It also takes up less space which is crucial for the environment you'll be working in. Atari 2600 games were less than 10K, on average, with most around 4K or less.
• 6502 Assembly is required because that's the language understood by the Atari 2600, which uses the MOS Technology 6507, a cheaper chip based on the MOS Technology 6502. It would be helpful to pick up a book on this language or use online resources. There are a lot out there.
• The Atari 2600 was a tricky beast to write for and a lot of it had to do with the Television Interface Adapter chip, which was the heart of the graphics and sound generation system. You should learn as much about this chip as possible and how it relates to putting graphics on the screen. As with most consoles and graphics systems today, you can access software-libraries that already deal heavily with displaying graphics on a screen, but in the old days, you had to take all of that into account and write it by hand. Good luck!

References & Resources

• 2600 101 by Kirk Israel
• Assembly language tutorial
• 2600 101 by Kirk Israel
• AtariAge.com - Atari console repository, includes links to homebrew games