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
A vertical flashing line that permits the user where text will be inserted.
Q. Illustrate basic working of Physical layer? Physical layer: Physical layer is concerned with sending raw bits between source and destination nodes over a physical medium.
Q. Copy file from a floppy disk to the hard disk? While using a PC, often you need to copy file from a floppy disk to the hard disk or vice-versa. For instance, you buy some s
Electronic Data Interchange (EDI ) is used by companies for transactions that happen on regular basis to a pre-determined format. It is one of the electronic commerce technologies.
Explain the term- macro? A term macro is a set of instructions, which can be executed repeatedly. It is useful for automating certain routine tasks like printing reports etc. T
The implementation of a (non-recursive) binary search of an array. The assumption is that a given array is sorted. We want to see if a particular value, that we'll call the target
Students are needed to work in group of 3 and make an Android mobile application falling under the following categories: Multimedia o Eg: Camera app, mp3 player, ga
Explain Tri-state logic inverter with the help of a circuit diagram. Give its Truth Table. Ans: Tri-state Logic Inverter: The functional diagram of Tri-state Logic Inve
Q. State the difference between following. i. RAM and ROM ii. SRAM and DRAM iii. Dynamic and static MOS memories
Why is XML superior to other forms of data exchange? The XML gives universal data format for integrated electronic business solutions. Other database systems and Relational dat
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd