Trend Posts
Author
View LUQMAN's profile
Friday, February 21, 2014
ASSUME CS: CODE
CODE
SEGMENT ;
code segment starts
START:
MOV BX, 00 ; initialize
counter BX as 00
REPEAT: PUSH
BX ; save the BX
value in stack memory.
MOV
AH, 07H ; BIOS
service number to clear the screen
MOV AL, 00H ; Number of lines to scroll; 00 blank screen.
MOV BH, 0FH ; attribute of character; 0F white and 00 black
MOV CX, 00H ; CH=00 Y coordinate of upper left corner and CL=00
X
; coordinate of upper right corner
MOV DH, 31H ; Number
of rows; Lower right row
MOV DL, 79H ; Number
of rows; Lower right row
INT
10H ; BIOS interrupt to clear the screen is
invoked
MOV
AH, 02H ;BIOS service number
to set the cursor
MOV BH, 00H ; set
video Page number to 0
MOV DH, 0CH ; store row number in DH (Y coordinate)
MOV DL, 25H ; store the column number (X) in DL register
INT
10H ; BIOS interrupt to set the cursor is
invoked
POP BX ; pop the counter
value stored in stack to BX
MOV AL, BL ; copy the 8 bit (1 byte) counter value in BL
to AL
AAM ; convert Hex value in AL to unpacked BCD
ADD AX, 3030H ; add 3030H to AX, to get the ASCII code of the converted no.
MOV CX, AX ;
store AX value temporally in CX
MOV DL, AH ; display the
upper digit of the counter value on the screen
MOV AH, 02H ; using 02H
service no. with DOS 21H interrupt.
INT 21H
MOV DL, CL ; display the
lower digit of the counter value on the screen
MOV AH, 02H ; using 02H service no. with DOS 21H
interrupt
INT 21H
CALL DELAY ; call
DELAY procedure, to provide some delay after each counter display
INC BL ; increment BL (counter value) by 1
CMP BL, 100 ; compare this
counter value in BL with 100
JNE REPEAT ; if the counter
value is < 100, then jump to label REPEAT
MOV AH, 0BH ; otherwise, check the keyboard status,
so that any key is
INT 21H ; pressed during counter display (00-99).
This can be done by
; using service no. 0BH with DOS 21H. If
any key is pressed,
; then AL is set to FFH
otherwise AL
= 00
CMP
AL, 00H ; compare AL with 00
JE START ; if AL=00,
then none of the key is pressed during counter display.
; so
jump to START and again display the counter value from 00-99
MOV
AH, 4CH ; otherwise if any key is pressed, then
terminate the program
INT 21H
DELAY
PROC NEAR ; start of delay procedure
PUSH CX ; save the values of CX and DX in stack,
since these registers
PUSH DX ; are used within the program
MOV DX, 0FFFH ; delay counter values
B2: MOV CX, 0FFFFH
B1: LOOP B1
DEC DX
JNZ B2
POP DX ; reload the original values of CX and DX
from stack
POP CX
RET ; return to calling
program
DELAY ENDP ;
end
of procedure
CODE ENDS ; end of code segment
END
START ; end of program
Output:
D:\MASM>
Masm 10a.asm;
D:\MASM>
Link 10a.obj;
D:\MASM>
10a.exe
Subscribe to:
Post Comments (Atom)
0 comments:
Post a Comment
You are very Important to Us...
STAY TUNE...