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

Simple instruction formats, Simple instruction formats: RISC uses simpl...

Simple instruction formats: RISC uses simple instruction formats. Usually only one or a few instruction formats are used. In these machines instruction length is fixed and alig

Principles of composition, PRINCIPLES OF COMPOSITION The principles of ...

PRINCIPLES OF COMPOSITION The principles of composition are the way that the elements of composition are used to achieve a particular purpose. Some of the main principles of co

Write a subroutine in c for toggling the cursor, Write a subroutine in C fo...

Write a subroutine in C for toggling the cursor using old directives. ; ; use small memory model for C - near code segment _DATA SEGMENT WORD   'DATA'   CURVAL EQU   [B

Make a generalize program to performs r-ary subtraction, Q. Make a genera...

Q. Make a generalize program that performs r-ary subtraction on two numbers using (r-1)'s and r's complement? Use input and output files.

Explain definition of fibonacci, Explain definition of fibonacci Where ...

Explain definition of fibonacci Where an input value gives a trivial result, it is returned directly, otherwise the function calls itself, passing a changed version of the inpu

What is clearquest, Rational ClearQuest is a change-request management tool...

Rational ClearQuest is a change-request management tool that tracks and handles defects and change requests all through the development process. With ClearQuest, you can manage eac

Fully parallel associative processor (fpap), Fully Parallel Associative Pro...

Fully Parallel Associative Processor (FPAP):  This processor accepts the bit parallel memory organisation. FPAP has two type of this associative processor named as: Word Org

Over fitting considerations, Over fitting Considerations : Hence in le...

Over fitting Considerations : Hence in left unchecked there backpropagation in multi-layer networks can be highly susceptible to overfitting itself to the training examples. B

Universal serial bus - computer architecture, Universal Serial Bus - comput...

Universal Serial Bus - computer architecture: USB   Universal Serial Bus   Speed Low-speed(1.5 Mb/s) High-speed(480 Mb/s) Full-speed(12 Mb/s)   De

write a ''c'' program to accept any 3 digit integer number, Write a 'C' pr...

Write a 'C' program to accept any 3 digit integer number from the keyboard and display the word equivalent representation of the given number

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