Analog to Digital Conversion Interface in 8086

;8086 Microprocessor interfaced with 8255 PPI and ADC
;Read Analog input at Channel 0 of ADC0809 IC and display the digital value in the Segment Display
   OUTPUT 2500AD
.ORG 2000H

DATA SEGMENT
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE,DS:DATA
START:
        MOV AX,DATA
        MOV DS,AX
        MOV AL,98H
        MOV DX,FFE6H
        OUT DX,AL
L2:
        MOV AL,00H
        MOV DX,FFE4H
        OUT DX,AL
        MOV AL,00H
        MOV DX,FFE2H
        OUT DX,AL
        MOV AL,02H
        MOV DX,FFE4H
        OUT DX,AL
        MOV AL,03H
        MOV DX,FFE4H
        OUT DX,AL
        MOV AL,01H
        MOV DX,FFE4H
        OUT DX,AL
        MOV AL,00H
        MOV DX,FFE4H
        OUT DX,AL
L1:
        MOV DX,FFE4H
        IN AL,DX
        RCL AL,01H
        JNC L1
        MOV AL,04H
        MOV DX,FFE4H
        OUT DX,AL
        MOV DX,FFE0H
        IN AL,DX
        MOV BL,00H
        MOV BH,00H
        DB 9AH,12H,0BH,00H,0FFH
        JMP L2
CODE ENDS
END