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

What is the window of the working set of a process, What is the window of t...

What is the window of the working set of a process? The window of the working set of a method is the total number in which the method had referred the set of pages in the work

Write a verilog code for synchronous and asynchronous reset, Write a Verilo...

Write a Verilog code for synchronous and asynchronous reset? Synchronous  reset, synchronous means clock dependent so reset must not be present in sensitivity disk eg: alway

Dbms, documentation for dbms report

documentation for dbms report

How to copy files from a drive and directory, Q. How to copy files from a d...

Q. How to copy files from a drive and directory? You can copy files from a drive and directory other that the currently selected one. However in that case, you need to speci

Define the full form of ssl, Define the full form of SSL SSL has becom...

Define the full form of SSL SSL has become fundamental to the spread of Internet community, and commerce and trade over Internet. Over years, the spread of its use for an incr

Syntax and semantics - first-order logic, Syntax and Semantics: Propos...

Syntax and Semantics: Propositional logic is prohibited in its expressiveness: so just to represent true and false facts for the world. By a type of extending propositional lo

What is co-operative process, What is co-operative process? A process i...

What is co-operative process? A process is co-operating if it can affect or be affected by the other processes implementing in the system. Any process that share data with othe

Calculate the complexity of sorting algorithms, How do you calculate the co...

How do you calculate the complexity of sorting algorithms? Find the complexity of Insertion sort and Bubble Sort.                 The difficulty of sorting algorithms depends o

Name the software required to run video conferencing, Name The software req...

Name The software required to run video conferencing The software and hardware required to run video conferencing is very sophisticated. Apart from obvious items (that is large

And-introduction rule, And-Introduction: In generally English says tha...

And-Introduction: In generally English says that "if we know that a lot of things are true, so we know that the conjunction of all of them is true", then we can introduce conj

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