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

Show the internet protocols, A communication protocol is an agreement which...

A communication protocol is an agreement which specifies a common language two computers use to exchange messages. For instance, a protocol specifies exact format and meaning of ev

How a file can be shared among different users, Discuss the different techn...

Discuss the different techniques with which a file can be shared among different users. Several popular techniques with that a file can be shared among various users are: 1

Explain problem-oriented and procedure-oriented language, Explain differenc...

Explain difference between Problem-oriented and procedure-oriented language. Problem-oriented and procedure-oriented language: The programming languages which can be utilized

Contact-based keyboards, Contact-based keyboards employ switches directly. ...

Contact-based keyboards employ switches directly. Though they have a comparatively shorter life they are the most preferred type these days because of their lower cost.  Three such

Scope of expert system, The scope of the experts system is very limite...

The scope of the experts system is very limited. It cannot work outside the field it is being used. The users knowledge is required to adjust to new situation. To reduce

Designing the instruction format, Q. Designing the instruction format is a ...

Q. Designing the instruction format is a complex art? Instruction Length Significance: It's the fundamental issue of the format design. It concludes the richness and flex

How does applet update its window when information changs, How does the App...

How does the Applet update its window when information changes? Whenever an applet requires to update the information displayed in its window, this simply calls repaint ( ) way

Megaflops, Speed in scientific computing is measured in megaflops, gigaflop...

Speed in scientific computing is measured in megaflops, gigaflops, teraflops and petaflops. A megaflop is 10 6 floating point arithmetic operations (+, -, *, /) in one second What

Layout for the assumed penalty, Solve the following 8-department problem us...

Solve the following 8-department problem using the MIP method.  What is the resulting layout and flow-distance score?  Note that the aspect ratio of each department should be 2.

What is the meaining of action implementing instruction, Action implementin...

Action implementing instruction's meaning are a actually carried out by ? Ans. By instruction execution, the meaning of action implementing instruction is actually carried out.

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