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

Mathematical simulation and modelling applications, Mathematical Simulation...

Mathematical Simulation and Modelling Applications The tasks include mathematical simulation and modelling need lots of parallel processing. Three fundamental formalisms in mat

Rsa encryption function- cryptography, The general method for constructing ...

The general method for constructing the parameters of the RSA cryptosystem can be described as follows: Select two primes p and q Let N = pq and determine ∅ (N) = (p - 1

What is the significance of the memory table ''screen'', What is the signif...

What is the significance of the memory table 'SCREEN'? At runtime, attributes for every screen field are stored in the memory table called 'SCREEN'.  We need not declare this

Give difference between assembler and compiler, Give difference between ass...

Give difference between assembler and compiler. Assembler: It is the translator for an assembly language of computer. An assembly language is a low-level programming language

Registers used in organisation of an associative memory, In the organisatio...

In the organisation of an associative memory, many registers are used: Comparand Register (C): This register is used to grasp the operands, which are being searched for, or

Where signalling transfer point exist, Signalling transfer point (STP) exis...

Signalling transfer point (STP) exist in (A) Strowger exchange                  (B)  SS7 (C)  Local area network                 (D)  PABX Ans: STP that is stand f

Basic need of search engines, Q. Basic need of Search Engines? Search E...

Q. Basic need of Search Engines? Search Engines are programs which search the web. Web is a big graph with pages being the nodes and hyperlinks being the arcs. Search engines c

Explain about cseg segment, CSEG SEGMENT  ASSUME CS:CSEG, DS:CSEG, SS:CS...

CSEG SEGMENT  ASSUME CS:CSEG, DS:CSEG, SS:CSEG  ORG 100h START:MOV AX, CSEG; Initialise data segment  MOV DS, AX; register using AX  MOV AL, NUM1; Take the first num

What are the methods for handling deadlocks, What are the methods for handl...

What are the methods for handling deadlocks?  The deadlock problem can be dealt with in one of the three ways:  a. Use a protocol to prevent or avoid deadlocks, make sure th

Define electronic data interchange, Define Electronic Data Interchange. ...

Define Electronic Data Interchange. An EDI stand for Electronic Data Interchange is used by organizations for transactions which occur on regular basis to a pre-determined for

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