TITLE        PROG4-1     SIMPLE DISPLAY PROGRAM
PAGE         60,132
             .MODEL SMALL
             .STACK 64
;--------------
             .DATA
MESSAGE DB           'This is a test of the display routine','$'
;--------------
             .CODE
MAIN         PROC    FAR
             MOV     AX,@DATA
             MOV     DS,AX
             CALL    CLEAR                   ;CLEAR THE SCREEN
             CALL    CURSOR          ;SET CURSOR POSITION
             CALL    DISPLAY         ;DISPLAY MESSAGE
             MOV     AH,4CH
             INT     21H                     ;GO BACK TO DOS
MAIN         ENDP
;---------------
;THIS SUBROUTINE CLEARS THE SCREEN
CLEAR        PROC
             MOV     AX,0600H               ;SCROLL SCREEN FUNCTION
             MOV     BH,07                  ;NORMAL ATTRIBUTE
             MOV     CX,0000                ;SCROLL FROM ROW=00,COL=00
             MOV     DX,184FH               ;TO ROW=18H,COL=4FH
             INT     10H                    ;INVOKE INTERRUPT TO CLEAR SCREEN
             RET
CLEAR        ENDP
;---------------
;THIS SUBROUTINE SETS THE CURSOR AT THE CENTER OF THE SCREEN
CURSOR       PROC
             MOV     AH,02              ;SET CURSOR FUNCTION
             MOV     BH,00              ;PAGE 00
             MOV     DH,12              ;CENTER ROW
             MOV     DL,39              ;CENTER COLUMN
             INT     10H             ;INVOKE INTERRUPT TO SET CURSOR POSITION
             RET
CURSOR   ENDP
;---------------
;THIS SUBROUTINE DISPLAYS A STRING ON THE SCREEN
DISPLAY      PROC
             MOV     AH,09                ;DISPLAY FUNCTION
             MOV     DX,OFFSET MESSAGE    ;DX POINTS TO OUTPUT BUFFER
             INT     21H                  ;INVOKE INTERRUPT TO DISPLAY STRING
             RET
DISPLAY      ENDP
             END     MAIN