What do you understand by scan codes, Computer Engineering

Assignment Help:

Q. What do you understand by Scan Codes?

A scan code is a code produced by a microprocessor in keyboard when a key is pressed and is unique to key struck. When this code is received by computer it reports an interrupt and looks up scan code table in BIOS and realize which keys have been pressed and in what combination. Special memory locations known as status bytes tell the status of locking and toggle keys for example Caps lock etc. Every key press produces two different scan codes - one on key-push down known as Make code and another on its popping back known as Break code. This two-key scheme enables the computer to tell when a key is held pressed down for example ALT key when pressing another key say CTRL-ALT-DEL.


Related Discussions:- What do you understand by scan codes

Calculate max distance so subscriber get speech reproduction, In a subscrib...

In a subscriber loop that contains a series resistance of 300 ohms to protect the batteries in the exchange, a normalized telephone draws 10 mA and its standard input d.c. resistan

Write a cgi program that prints date and time, Write a CGI program that pri...

Write a CGI program that prints date and time at which it was run. #!/bin/sh # # CGI script that prints the date and time at which it was run # # Output the documen

Explain the violating basic security principles, Explain the violating basi...

Explain the violating basic security principles There are drawbacks to permitting users to access the Intranet as well as not permitting them. A simple consideration such as a

What are the primary models of supply chain management, What are the primar...

What are the primary models of Supply Chain Management? Two Primary models of Supply Chain Management are illustrated below: a. Porter’s Value Chain Model and b. Supply

Unit resolution, Unit Resolution: By assuming that we knew the sentenc...

Unit Resolution: By assuming that we knew the sentence as "Tony Blair is prime minister or may the moon is made of blue cheese", is true or we later found out that the moon is

Explain the main tags of wireless markup language, Discuss the main tags of...

Discuss the main tags of WML. Tag Definition of Wireless Markup Language: This defines the starting and the ending of the page, as .   this explains

Objectives-parallel computer architecture , Objectives After going thro...

Objectives After going through this part, you will be capable to: Examine the meaning of Pipeline processing and explain pipeline processing architectures; Classify

Design odd-even transposition algorithm, Q. Design Odd-Even Transposition A...

Q. Design Odd-Even Transposition Algorithm? Algorithm: Odd-Even Transposition for I=1 to N     {            If (I%2 != 0) //i.e. Odd phase            {

What are the digital certificates of hardware computations, What are the Di...

What are the Digital certificates of hardware computations Digital certificates are highly dependent on hardware computations, it is essential that mechanisms are evolved to i

Describe in brief about the internet, Describe in brief about The internet ...

Describe in brief about The internet Web sites need to be set up to maximise information supplied to customers and to ensure they are as self-contained and helpful as possible.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd