oldcomputernerd.com/md/Atari/entries/two-plus-two.md

Two-Plus-Two

10 ;
20 ;ADDNRS.SRC
30 ;
40        *=$0600    ; Begin program at 1536 decimal.
50 ;
52 ;  See notes below this snippet for details
54 ;
60        CLD        ; Clear Decimal Mode 
70 ADDNRS CLC        ; Clear Carry
80        LDA #2     ; Load Accumulator From Immediate 2
90        ADC #2     ; Add Immediate 2 To Accumulator With Carry
100       STA $CB    ; Store Accumulator To Location 203
110       RTS        ; Return To Stack
120       .END       ; Program End Macro