This preview shows page 1. Sign up to view the full content.
Unformatted text preview: function keys. These templates are usually made of
plastic that nicely fit over the keyboard. The functionality 01 the various function keys is
written on tpp of the plastic at the positions of those function keys. With this, a used need
not remember the functions assigned to different keys by different software packages.
Software Simulated Keys
We often come across the situation of entering a non-standard character such as "a" or
"±", or a phrase or name such as "Prentice-Hall of India" again and again while preparing
a particular document. To allow faster entry of data, a user may reassign a keyboard key
to produce them. For example, a user may write a software to reassign the character "#"
to the name "Prentice-Hall of India" so that whenever he/she enters the character "#"
from the keyboard, the system automatically enters "Prentice-Hall of India" in place of
the character #. Such arrangements of making the key produce something different from
what it is normally supposed to produce is known as software simulation of the key.
Almost all keyboards are designed with the auto repeat feature. According to this feature,
if a key remains pressed for the auto repeat initial delay period (usually of the order of
300 milliseconds),, then the character or the functionality of the key starts auto-repeating.
For example, if the key with the character "a" is kept pressed, then the characters
"aaaaa....." will start appearing on the terminal screen till it is kept pressed. This feature
facilitates faster data entry when the same character is to be entered multiple times or
when multiple lines or pages have to be skipped.
A keyboard buffer is a small memory inside either the terminal or the keyboard in which
each keystroke is first saved before being transferred to the computer's main memory for
processing. The keyboard buffer usually has capacity to save from a few tens to a few
hundreds of keystrokes. Storing of keystrokes in keyboard buffer instead of sending them
directly to the main memory makes the user interaction with the...
View Full Document
This document was uploaded on 04/07/2014.
- Spring '14