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
Propositional Inference Rules -Artificial intelligence : Equivalence rules are specifically useful because of the vice-versa aspect,that means we can discover forwards andbackw
Basic Concept of Data Parallelism Thinking the condition where the same problem of submission of „electricity bill? is Handled as follows: Again, three are counters. Howeve
Analysis: Basically, it is the process of determining what requirement to be done before how it should be done. In order to accomplish this, the developer shows the existing sy
What are preprocessor directives? Preprocessor directives: These are the commands given to a program called as pre-processor that processes the source code before it passes by
A weighted resistor digital to analog converter using N bits requires a total of ? Ans. Digital to analog converter, a weighted resistor using N bits needs a total of N precisi
What are pages? All programs and date are composed of fixed length units known as pages. Each page consists of blocks of words that occupy contiguous locations in main memory
Q. Program for interchanging the values of two Memory locations? Program for interchanging the values of two Memory locations ; input: Two memory variables of same size:
Q. Introduction to the Operating System? An Operating system is software that creates a relation between the User, Hardware and Software. It is an interface between the all.
Compare single bus structure and multiple bus structure? A system that having only one bus(i.e only one transfer at a time) is known as a single bus structure. A system is know
States the term IP addresses? IP address considers to the name of a computer onto a network, as the Internet. a. An Identifier for a device or computer onto a TCP/IP network
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