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.

Posted Date: 7/20/2013 2:42:30 AM | Location : United States

Ask an Expert

Related Discussions:- What do you understand by scan codes, Assignment Help, Ask Question on What do you understand by scan codes, Get Answer, Expert's Help, What do you understand by scan codes Discussions

Write discussion on What do you understand by scan codes
Your posts are moderated

Write your message here..

Related Questions

Illustrate the following list of consideration of Laptop, Illustrate the fo... Illustrate the following list of consideration of laptop computers The following is a list for consideration: -  The processor must consume as little power as possible thus

Explain the ccitt hierarchical structure of routing, Explain the CCITT hier... Explain the CCITT hierarchical structure of routing using block schematic. In right-through routing the originating exchange finds the whole route from source to destination. N

What is performance testing in loadrunner, Timing for both read and update ... Timing for both read and update transactions should be gathered to verify whether system functions are being performed in an acceptable timeframe. This should be done standalone an

Computer architecture, pipelining hazards pipelining hazards

Sun and nis law, Sun and Ni's Law The Sun and Ni's Law is a generalizat... Sun and Ni's Law The Sun and Ni's Law is a generalization of Amdahl's Law as well as Gustafson's Law. The fundamental idea underlying the Sun and Ni's Law is to find the soluti

What are the different layers in r/3 system, What are the different layers ... What are the different layers in R/3 system? There are three layer:- Presentation Layer. Application Layer. Database Layer.

Block diagram of a microcomputer system, Q. Block Diagram of a Microcompute... Q. Block Diagram of a Microcomputer System? Before going on to consider the I/O sub/systems of a computer, let's discuss how a digital computer system can be realized by a micr

Explain the design procedure for flip flop, Explain the Design Procedure fo... Explain the Design Procedure for Flip Flop? The design procedure as follows. 1) Acquire the clear description of the desired flip flop X. 2) Acquire the present state- next

Determine the equivalent binary form of decimal number, Solve the equation ... Solve the equation 23.6 10 = X 2 for X Ans. 23.6 10 = X 2 So as to find X, firstly convert the Decimal number 23.610 in its Binary form. After that take the decimal inte

Poor human support - obstacle to information system, Poor human support - O... Poor human support - Obstacle to Information System The full utility of an IS will only be realised if it is properly supported by the users. Technology is never a solution in