geogray wrote:Atari 800 game programming...now THATS impressive. If I recall, they were a bear to code for..or am I thinking of the VCS?
Probably the VCS.
The Atari 800 generally was programmed in BASIC with assembly language subroutines. You would POKE various values into specific places in the memory space in order to activate hardware functions (such as changing screen resolution).
The display was a conventional television set. When the raster beam hit the end of the last scan line, the beam would start to travel to the upper left corner, and the vertical blank interrupt would trigger. You would attach to this an assembly language routine to be run, to perform any periodic operations (like polling the joystick to scroll the game screen).
The easiest way to insert such an assembly language subroutine was very Rube Goldberg. You'd write it in assembly language and compile it. You'd take the object code and turn it into a BASIC language string (using all sorts of weird font characters). In you BASIC program, you'd create a string variable, assign the object code "string" to it, and pass the address of the string variable to the vertical blank interrupt.
Those were the days.