*=$PRINTV
  .WORD  PHOPEN-1 ; DEVICE OPEN
  .WORD  PHCLOS-1 ; DEVICE CLOSE
  .WORD BADST-1 ; DEVICE READ-NOT IMPLEMENTED
  .WORD  PHWRIT-1 ; DEVICE WRITE
  .WORD  PHSTAT-1 ; DEVICE STATUS
  .WORD  BADST-1 ; SPECIAL-NOT IMPLEMENTED
  JMP PHINIT ; DEVICE INITIALIZATION