10;output a string into the top left of the screen
20        ORG   0100H       ;Start at addr 0x100
30START:  LD    HL,DATA     ;Load the start address of the string
40        LD    B,0DH       ;The length of the string (max 255 chars)
50        LD    DE,0H       ;Start in the top left corner (D=0-3 -> row; E=0-23 column)
60        CALL  84CDH       ;Call the str_out function in ROM
70        RET               ;Return from call
80DATA:   DB    'HELLO, WORLD!'
90        END               ;End marker for the assembler