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

Determine the output of SR flip flop when S=1 and R=0, The output of SR fli...

The output of SR flip flop when S=1, R=0 is ? Ans. When for the SR flip-flop S=set i/p R=reset i/p, as S=1, R=0, Flip-flop will be set means output will be one.

Two parallel fetch-implement, Take a CPU that shows two parallel fetch-impl...

Take a CPU that shows two parallel fetch-implement pipelines for superscalar processing. Determine the performance improvement over scalar pipeline processing and no-pipeline proce

Define encapsulation- object oriented technology, Define Encapsulation- obj...

Define Encapsulation- object-oriented technology Encapsulation also called as information hiding, is the characteristic of separating the external aspects of an object, from t

Define various system, Define various system? Single job system: Only...

Define various system? Single job system: Only one program may be run at a time, and therefore only one person might be work on a machine at one time.  Multi job system:

What are stacks, What are stacks? A stack  is an abstract data type in...

What are stacks? A stack  is an abstract data type in which items are additional to and removed only from one end known as TOP. For example, consider the pile of papers on you

Characteristics of D/A converter, What are the specifications/characteristi...

What are the specifications/characteristics used by the manufacturers to describe a digital to analog converter? Explain each one briefly. Ans: D/A converter characteristics

Circles in the visualization, To sktech the circles in the visualization, y...

To sktech the circles in the visualization, you need to use the paramteric equation of a circle (x = r cos (Θ), y = r sin(Θ). A circle can be shown as a polygon where the points of

Describe the working of components of i-way infrastructure, Describe the wo...

Describe the working of components of I-way Infrastructure. Working of I-way Infrastructure components: a. Consumer access equipment shows a critical category, it is the abs

What are the two aspects of locality of reference, What are the two aspects...

What are the two aspects of locality of reference? Define them. Two aspects of locality of reference are temporal aspects and spatial aspect. Temporal aspect is that a r

Define overflow, Define Overflow.  An overflow is a problem in digital ...

Define Overflow.  An overflow is a problem in digital computer due to the width of registers is finite. A result that contains n+ 1 bit cannot be accommodated in a register wit

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