Hello:
I have been learning Atari 2600 programming on my Mac. I have read the beginner information online, and am able to program simple things such as colors and objects. I have also been hacking code and changing things. I am having difficulty understanding or finding resources on some commands at the beginning of the programs which I have hacked. For example, I know that STARTSCREEN changes the bottom position of the screen because I have changed its value and have observed it. However, I haven't found a resource which lists this command and what the variable represent. I know that one game starts at $54.
Here are other commands which I do not have a solid definition for:
NTSC = 0
PAL = 1
COMPILE_VERSION = NTSC
; Position equates
SCREENSTART = $54
UP = SCREENSTART
DOWN = $04
LEFT = $02
RIGHT = $A0
SCOREOFFSET = $31
MAXSCORE = $42
There is also code at the beginning of PITFALL such as SCREEN_SAVER, TRAINER FILLOPT, etc.
Is there a reference guide for these commands? Thanks!
I have been learning Atari 2600 programming on my Mac. I have read the beginner information online, and am able to program simple things such as colors and objects. I have also been hacking code and changing things. I am having difficulty understanding or finding resources on some commands at the beginning of the programs which I have hacked. For example, I know that STARTSCREEN changes the bottom position of the screen because I have changed its value and have observed it. However, I haven't found a resource which lists this command and what the variable represent. I know that one game starts at $54.
Here are other commands which I do not have a solid definition for:
NTSC = 0
PAL = 1
COMPILE_VERSION = NTSC
; Position equates
SCREENSTART = $54
UP = SCREENSTART
DOWN = $04
LEFT = $02
RIGHT = $A0
SCOREOFFSET = $31
MAXSCORE = $42
There is also code at the beginning of PITFALL such as SCREEN_SAVER, TRAINER FILLOPT, etc.
Is there a reference guide for these commands? Thanks!