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

Component fulfil this requirement, A component has the time to failure dist...

A component has the time to failure distribution that is modelled as the Weibull distribution with shape parameter 3 and scale parameter of 36 months. This component is planned to

Concurrently read concurrently write, Q. Concurrently read concurrently wri...

Q. Concurrently read concurrently write? It is one of the models derived from PRAM. In this model the processors access the memory locations simultaneously for reading and writ

How firewalls operate, Firewalls operate by Creening packets to/from th...

Firewalls operate by Creening packets to/from the Network and give controllable filtering of network traffic.

Explain about programmer visible registers, Q. Explain about Programmer Vis...

Q. Explain about Programmer Visible Registers? Programmer Visible Registers: These registers can be employed by machine or assembly language programmers to minimize reference

Explain switch statement, Switch This is another form of the multi way ...

Switch This is another form of the multi way decision. It is well structured, but can only be used in certain cases where; Only one variable is tested, all branches must

Visibility, hidden edge/surface removal

hidden edge/surface removal

How much CMOS circuits consume power, CMOS circuits consume power ? An...

CMOS circuits consume power ? Ans. As in CMOS one device is ON and one is Always OFF therefore power consumption is low or can say less than TTL.

How different are interface and abstract class in .net, How different are i...

How different are interface and abstract class in .Net? Abstract classes cannot be instantiated it can have or can't have abstract method basically known as must inherit as th

Avoiding local minima, Avoiding Local Minima: However the error rate o...

Avoiding Local Minima: However the error rate of multi-layered networks over a training set could be calculated as the number of mis-classified examples. So always keep in rem

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