Information Technology Reference
In-Depth Information
Programmer
A programmer writes the instructions that become
computer programs. Whether it's an operating system, a
utility, or a game, a programmer takes a general concept
like “open a dialog box with user controls for adjusting
the graphics quality” and makes it a reality by writing the
exact instructions needed, line by line. The programmer
then compiles those instructions into a usable program,
or combines them with the instructions written by another
programmer or group of programmers to make a larger
program. More experienced programmers may also par-
ticipate in developing the requirements for a program. A
programmer should have at least an associate degree in
Computer Technology, Computer Science, or Information
Technology, and should be familiar with at least two or
three different programming languages.
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Understanding System Software
System software
includes BIOS, the operating system, and utility
programs that perform system maintenance and protection tasks such as
error correction and backup. Let's look at each category in more detail.
system software
Software that starts the
computer and keeps it running, performing basic
system tasks such as running applications, man-
aging files, and correcting errors.
The System BIOS
As you learned in
Chapter 2, “The System Unit,”
the Basic Input/
Output System (BIOS) is the built-in software on the motherboard that
starts the computer. It performs a power-on self-test (POST) at start-
up, which ensures that all the critical hardware devices are functioning
properly, including the CPU, the RAM, and the motherboard. If the
hardware passes the tests, the BIOS looks for an operating system on
one of the available drives, and then passes off control to the operating
system to complete the boot process. The BIOS has a list of default set-
tings it uses for managing memory and devices, but those settings can be
overridden by user settings that you specify.
The Operating System
The BIOS starts the computer at a basic level, but the operating system
does the bulk of work to keep it running and to help the user accomplish
tasks. Remember from
Chapter 1, “Computer Basics,”
that the operating
system performs these important functions (see Figure 4.1):
◾
It provides the user interface that humans use to communicate
commands and receive feedback.
◾
It communicates with the hardware, instructing it to take action to
accomplish tasks. For example, it communicates with the keyboard
and mouse to accept input, and it communicates with the display
screen to show output.
◾
It runs applications and enables humans to interact with them.
◾
It controls and manages the file storage system.
