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
What is Block scope Block scope: The variables with block scope appear in a block or within the list of formal parameter declarations in a function definition. It is visible
Define emulation. Given a computer with a particular instruction set, it is possible to explain additional machine instructions and execute them with extra micro routines. Emul
What is elapsed time of computer system? The total time to implement the total program is known as elapsed time. It is affected by the speed of the processor, the disk and the
Q. Explain about parallel programming environment? The parallel programming environment comprises of a debugger, an editor, performance evaluator, programme visualizer for incr
What is a Table attribute? The table's attributes verifies who is responsible for maintaining a table and which types of access are permitted for the table. The most signific
Q. Define Public Identifiers? Public Identifiers: A public identifier is one which is defined within one module of a program however potentially accessible by all of the other
Utilization Summary The Utilization Summary shows the status of each processor i.e. how much time (in the form of percentage) have been spent by every processor in busy mode, o
The commands through Which an ABAP/4 Module can "branch to " or "call" the next screen are Set screen Call screen , Leave screen, Leave to screen
Define the PUBLIC and EXTRN directives- Assembler directives PUBLIC and EXTRN directives are very significant to modular programming. PUBLIC used to declare that labels of data
Pipelined Processor Having discussed pipelining; now we can describe a pipeline processor. A pipeline processor can be distinct as a processor that consists of a series of proc
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