display.asm

Display the string on the screen and can change the display speed

;*********
;display.asm by zhangyu
;*********
DATA SEGMENT
STR1 DB 2,8,14,17,24,36,44,55,75 ;the  speed levels
STR2 DB 'sorry!only the number of 0 tp 9 is available!','$'
DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA 
START:
MOV AX,DATA
MOV DS,AX 
MOV SI,0
REPLAY:
 MOV DL,2fH

 ADD DL,1
POINTER:
 MOV AH,02H
 INT 21H
 MOV BL,STR1[SI]
 CALL DELAYED
 INC DL
 CMP DL,39H
 JA REPLAY
 JMP POINTER 
 E_OUT:
 MOV AH,4CH
 INT 21H
DELAYED PROC NEAR
 PUSH DX
  
 DE_GOON:
 MOV AH,0CH ;clear the keyboard buffer		 
 INT 21H	
 MOV CX,5000h  ;the delayed time
DEL_LOOP:
	
 MOV AH,01H
 INT 16H
 JNZ NOSTRING
 LOOP DEL_LOOP
 DEC BX
 JNZ DE_GOON
 POP DX
 RET
DELAYED ENDP
NOSTRING:
  CMP AL,0DH
  JZ E_OUT  
  SUB AL,30H
  CMP AL,09 ;if the number if beyond 9
  JA warning;then show the warning message
  CBW    ;extend 8 to 16 bit
  MOV SI,AX
  MOV DX,SI
  ADD DL,30H
  MOV AH,02H
  INT 21H
  JMP POINTER 
warning:
call one
LEA DX,STR2	
MOV AH,09H
INT 21H
call one
jMP START 
ONE PROC NEAR
    PUSH DX
    MOV DL,0DH
    MOV AH,02H
    INT 21H
    MOV DL,0AH
    MOV AH,02H
    INT 21H
    POP DX
    RET
ONE ENDP
CODE ENDS
    END START