ORG      $5000
BUFSIZ    EQU      80              ;input buffer size
OPSTK     DS.B     20              ;size of operations stack
INPUTBUF  DS.B     BUFSIZ
START     LEA      INPUTBUF,A0     ;load address of input buffer into A0
          MOVE.W   #BUFSIZ,D0      ;set D0 to size of input buffer
                                   ;(A0) = address of input,
                                   ;(D0.W) = max number of characters to read
                                   ;on input (D0.W) is # of characters to input
          JSR      STRIN           ;get input
          JSR      STROUT          ;echo input
          SUBQ     #2,D0           ;adjust character count for DB instruction
          LEA      INPUTBUF,A1     ;set A1 to top of stack
SCANNEXT  CMPI.B   #'0',(A0)       ;input='0'?
          BLT.S    EVALUATE        ;if input<0 then input is operator
          MOVE.B   (A0)+,-(A1)     ;push input onto stack
          SUBI.B   #'0',(A1)       ;convert stack entry to binary
          BRA.S    CHKCNT          ;test for more input
EVALUATE  MOVE.B   (A1)+,D2        ;pop the operand stack
          MOVE.B   (A1)+,D1
          CMPI.B   #'*',(A0)+      ;is operand an '*'?
          BEQ      ANDOP           ;Yes it is - goto AND operand
          OR.B     D1,D2           ;otherwise OR arguements
          BRA.S    PUSHOP
ANDOP     AND.B    D1,D2           ;AND arguements
PUSHOP    MOVE.B   D2,-(A1)        ;push result onto stack
CHKCNT    DBF      D0,SCANNEXT
PUTANS    ADDI.B   #'0',(A1)       ;convert stack to ASCII
          MOVEA.L  A1,A0           ;set up pointer to output, i.e. A0
          MOVE.W   #1,D0           ;set up # of characters to output, i.e. D0.W
          JSR      STROUT
          JSR      NEWLINE