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

Embedded systems and the system in which rtos is running, Explain What is t...

Explain What is the difference among embedded systems and the system in which RTOS is running? Ans) Embedded system can have RTOS and cannot have also. It depends on the requi

Mplement a second-order low-pass filter using the finite dif, you will impl...

you will implement a second-order low-pass filter using the finite difference method. The finite difference method is a useful mathematical method that is used to numerically solve

What is graceful degradation, What is graceful degradation? In multipro...

What is graceful degradation? In multiprocessor systems, failure of one processor will not halt the system, but only slow it down by sharing the work of failure system by other

Decision trees - artificial intelligence, Decision Trees - Artificial intel...

Decision Trees - Artificial intelligence: Suppose you just ever do four things at the weekend: go shopping, watch a film, play tennis or just stay inside.  What you do depends

why doesn''t c have nested functions, It's not trivial to execute nested f...

It's not trivial to execute nested functions such that they have the proper access to local variables in the having function(s), so they were deliberately left out of C as a simpli

#project, how to build PVR set-top box using raspberry

how to build PVR set-top box using raspberry

Applications of linked list, What are the Applications of Linked List are ...

What are the Applications of Linked List are a) Fixed block storage allocation b) garbage collection

Example of calculate maximum access time & cost of switch, Calculate the ma...

Calculate the maximum access time that can be permitted for the data and control memories in a TSI switch with a single input and single output trunk multiplexing 2500 channels. Al

Analog-to-digital conversion process, A stationary random displacement sign...

A stationary random displacement signal was digitised at 64 samples a second and analysed to obtain an auto-spectral density.  The signal was calibrated in mm units.  The frame siz

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