Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
INT 21H supports about 100 different functions. A function is recognised by putting the function number in AH register. For illustration if we want to call function number 01 then we place this value in AH register first by employing MOV instruction and after that call INT 21H:
Some significant DOS function calls are:
DOS
Function Call
Purpose
Example
AH = 01H
For reading a single character from keyboardand echo it on monitor. The input value is put inAL register.
To get one character input in a variable in data segment you may include the following in the code segment:
MOV AH,01
INT 21H
MOV X, AL
(Please note that interrupt call will return value in AL which is being transferred to variable of data segment X. X must be byte type).
AH = 02H
This function prints 8 bit data (normally ASCII) that is stored in DL register on the screen.
To print a character let say '?' on the screen we may have to use following set of commands:
MOV AH, 02H;
MOV DL, '?'
AH = 08H
This is an input function for inputting one character. This is same as AH = 01H functions with the only difference that value does not get displayed on the screen.
Same example as 01 can be used only difference in this case would be that theinput character wouldn't get displayed
MOV AH, 08H
AH = 09H
This program outputs a string whose offset is stored in DX register and that is terminated using a $ character. One can print newline, tab character also.
To print a string "hello world" followed by a carriage return (control character) we may have to use the following assembly program segment.
Example of
CR EQU ODH
; ASCII code of carriage return.
DATA SEGMENT
STRING DB 'HELLO WORLD', CR, '$'
DATA ENDS
CODE SEGMENT
:
MOV AX, DATA
MOV DS, AX
MOV AH, 09H
MOV DX, OFFSET STRING
; Store the offset of string in DX register.
AH = 0AH
For input of string up to 255 characters. The stringis stored in a buffer.
Look in the examples given.
AH = 4CH
Return to DOS
Q. Show typical microprocessor system architecture? A microprocessor system bus consists of three physical buses: the address bus, the data bus, and the control bus. The types
Specify the goals of parsing. Goals: a. To check the validity of source string b. To agree on the syntactic structure of a source string. For invalid string this rep
CIDR stands for? CIDR stands here for Classless Inter Domain Routing.
Q. Describe the Size and Speed of Scanners? Before actual scanning, a quick, low resolution scan known as pre-scan is made to preview the image and select scanning area. After
Define the node of object oriented modeling A node is a physical element which exists at runtime and represents a computational resource usually having a large memory and often
Determine the uses of Programming Language Interface PLI is used for implementing system calls that would have been hard to do otherwise (or impossible) using Ve
area under curve
What are the advantages of having e-commerce over extranets? Extranets are about " joining up" the supply chain-suppliers, resellers, distributors, customers, etc.-enabling
Q. Develop a Menu driven program with following menu: a. Binary to Decimal b. Binary to Octal c. Binary to Hexadecimal d. Exit (Put proper validation for input
What logic gets synthesized when I use an integer instead of a reg variable as a storage element? Is use of integer recommended? An integer can take place of a reg as
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd