.target "8080"
 .format "bin"
 .org $100
 
bdos    .equ    $0005           ; BDOS entry point
start:  mvi     c,9             ; BDOS function: output string
        lxi     d,msg           ; address of msg
        call    bdos
        ret                     ; return to CCP
msg    .text    "Hello, world!$"
       .end