;Atari 2600 Initialization Code - C02 Assembly Language File
;Based on Batari Basic Initialization Code

START:  SEI         ;Disable Interrupts
        CLD         ;Disable Decimal Modes
        LDY #0      ;Set Y-Index to $00
        LDA $D0     ;If Location $D0
        CMP #$2C    ;  Does Not Contain $2C
        BNE IS2600  ;And
        LDA $D1     ;  Location $D1 
        CMP #$A9    ;  Does Not Contain $D1
        BNE IS2600  ;Then
        DEY         ;  Set Y-Index to $FF
IS2600: LDX #0      ;
        TXA         ;
CLRMEM: INX         ;Clear TIA Registers and RAM
        TXS         ;  by Cycling Through All Stack Locations
        PHA         ;  and Pushing 0
        BNE CLRMEM  ;  which leaves Stack Pointer at $FF
        TYA         ;Copy 2600 Flag to Accumulator
        JMP MAIN