MY8255_A   EQU  9C60H
MY8255_B   EQU  9C61H
MY8255_C   EQU  9C62H
MY8255_M   EQU 9C63H
DATAS SEGMENT
X DB ?
DATAS ENDS
CODE  SEGMENT
   ASSUME  CS:CODE,DS:DATAS
START:
      MOV AX,DATAS
      MOV DS,AX
      MOV DX,MY8255_M
      MOV AL,82H
      OUT DX,AL
   A0:MOV DX,MY8255_B
       IN AL,DX
    MOV X,AL
      MOV DX,MY8255_A
      OUT DX,AL
      CALL DELAY
   XOR X,0FEH
       JZ CIRCUIT1
      MOV X,AL
      XOR X,0FCH
       JZ CIRCUIT2
      MOV X,AL
      A1:XOR X,0F8H
       JZ CIRCUIT3
      MOV X,AL
      XOR X,0F0H
       JZ J4
MOV X,AL
      XOR X,07FH
       JZ J5
  MOV X,AL
      XOR X,03FH
       JZ J6
MOV X,AL
      XOR X,01FH
       JZ J7
MOV X,AL
      XOR X,0FH
       JZ J8
      JMP A0
CIRCUIT1:ROL AL,1
        MOV AH,AL
        MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         CMP AL,0FEH
          JZ JUMP1
         JMP A0
         JUMP1:MOV AL,AH
         JMP CIRCUIT1
CIRCUIT2:MOV CL,2
ROL AL,CL
         MOV AH,AL
 MOV DX,MY8255_A
                OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         CMP AL,0FCH
          JZ JUMP2
         JMP A0
         JUMP2:MOV AL,AH
         JMP CIRCUIT2
CIRCUIT3:MOV CL,3
ROL AL,CL
         MOV AH,AL
 MOV DX,MY8255_A
               OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         CMP AL,0F8H
       JZ JUMP3
         JMP A0
         JUMP3:MOV AL,AH
   JMP CIRCUIT3
J4:JMP  CIRCUIT4
J5:JMP  CIRCUIT5
J6:JMP CIRCUIT6
J7:JMP CIRCUIT7
J8:JMP CIRCUIT8
CIRCUIT4:MOV CL,4
         ROL AL,CL
          MOV AH,AL
 MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
        CMP AL,0F0H
         JZ JUMP4
         JMP A0
         JUMP4:MOV AL,AH
       JMP CIRCUIT4
 CIRCUIT5:ROR AL,1
        MOV AH,AL
        MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         XOR AL,07FH
          JZ JUMP5
         JMP A0
   JUMP5:     MOV AL,AH
         JMP CIRCUIT5
CIRCUIT6:MOV CL,2
ROR AL,CL
        MOV AH,AL
        MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
        XOR AL,03FH
          JZ JUMP6
         JMP A0
         JUMP6:MOV AL,AH
         JMP CIRCUIT6
CIRCUIT7:MOV CL,3
ROR AL,CL
        MOV AH,AL
        MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         XOR AL,01FH
          JZ JUMP7
         JMP A0
         JUMP7:MOV AL,AH
         JMP CIRCUIT7
CIRCUIT8:MOV CL,4
ROR AL,CL
        MOV AH,AL
        MOV DX,MY8255_A
         OUT DX,AL
         CALL DELAY
         MOV DX,MY8255_B
         IN AL,DX
         XOR AL,0FH
          JZ JUMP8
         JMP A0
         JUMP8:MOV AL,AH
         JMP CIRCUIT8
    DELAY:MOV CX,0FFFH
      D1:MOV BX,0FFFFH
      D2:DEC BX
         JNZ D2
        LOOP D1

        RET
   CODE  ENDS
          END START