5 REM 12-BIT-PORT $600 HOCHZAEHLEN
   10 PRINT CHR$(12);"PORT $600 I/O"
   20 FOR N=0 TO 15:REM MSB
   25 FOR A=0 TO 255:REM LSB
   30 POKE 1536+N,A
   40 NEXT A
   50 GOSUB 100
   60 NEXT N
   90 GOTO 20
  100 I=PEEK(1536)
  110 CURSOR 0,4:PRINT "PORT $600:";I
  120 I=PEEK(1552)
  130 CURSOR 0,5:PRINT "PORT $610:";I  
  150 RETURN