init.mac

.z80

unix  equ       8
BDOS  equ       5

begin:
      ld        hl,12         ; fork
      push      hl
      call      unix          ; de=PID
      pop       hl
      ld        hl,hellostr
      jp        nc,printstr   ; if no error
      ld        hl,errorstr
      ld        e,c
      ld        d,b           ; error code
      ld        bc,50
printstr:
      push      bc
      push      hl
      push      de
      ex        de,hl         ; de=str
      ld	c,9
      call	BDOS
      pop       de
      call      PRHEX
      pop       hl
      pop       bc
      djnz      printstr
      ret
;
PRHEX:  LD      A,D
        CALL    HOUTF0
        LD      A,D
        CALL    HOUT0F
        LD      A,E
        CALL    HOUTF0
        LD      A,E
        JR      HOUT0F
;
HOUTF0: RRCA
        RRCA
        RRCA
        RRCA
HOUT0F: AND     0FH
        ADD     A,'0'
        CP      '9'+1
        JR      C,HOUT
        ADD     A,7
HOUT:   PUSH    DE
        LD      E,A
        LD      C,2
        call    BDOS
        POP     DE
        RET
;
hellostr:
      db	13,10,'Hello world! I am INIT, pid=$'
errorstr:
      db	13,10,'Error $'
END   begin