But, even if Atari wished to keep it closed, what was the coding process? I mean, did they assemble it in a third-party computer which was unable to run the code? How did they try even if the code ran at all? Did they have to burn a cartridge just to check if the code started to run? I supposed Atari used some of their computers, attached to a 2600 board in some way, so that they didn't have to burn a cartridge just for checking if aliens look nicer in green or red...