Chapter 14 computing by

sanchezoier — 2025-10-08 09:53:29 UTC

Hardware is the part of the computer that we can

touch.

The hardware is the components that are

interconnected. The computer needs all those

components, but they are independent and we can

change any of them.

The basic components are the CPU, the memory, the

graphics card and the peripherals.

sanchezoier — 2025-10-08 09:59:20 UTC

Computers are not intelligent; they are tools that follow instructions perfectly and quickly. They follow instructions from the user and from the computer programmer. Applications (word processors, video games, etc.) are sets of instructions.

sanchezoier — 2025-10-09 10:00:33 UTC

The CPU (Central Processing Unit) is a big, green,

plastic board with a lot of chips and many other

electronic components mounted on it.

The central processing unit is also called "the

processor". It is the "brain" of the computer; it looks

at the information and takes decisions based on

logic.

sanchezoier — 2025-10-09 10:29:36 UTC

Software is the part of the computer that we can't touch.

It is the logic that the computer follows.

The programmer writes instructions. A set of instructions is a "program". When we use a

program, the computer follows the instructions in the program.

The Operating System (OS)

sanchezoier — 2025-10-10 06:37:49 UTC

There is one OS per computer; not more, not less.

The OS defines the internal logic for the functioning of the computer.

To program the OS, we must know which are the components of the hardware and how

they are connected.

For example, when we tell the computer to switch off, the OS decides to first close the

applications, then to transfer all data from the RAM to the HD, and finally to switch it self off.

Operating systems evolve along with computers. In the 1980s only one user could interact

with a computer and computers only had text, not images.

Computers had one processor, one application, one floppy disc, one keyboard and one

screen.

The OS was programmed only to manage those hardware components.

In those days, the OS was stored on a floppy disk, which was loaded after switching on the

computer.

The user first loaded the OS, (stored on an external disk) and then the application (stored

another external disk). The user could then start to use the application.

Today's OS

sanchezoier — 2025-10-10 06:40:22 UTC

It is stored in the hard disc (the applications are also stored in the HD).

It can manage multiple applications at the same time.

It has a graphic display, so we can interact with the computer using a mouse.

It can connect to the internet.

Today, the most common operating systems are those sold by

Microsoft: Windows Vista, Windows 7...

Microsoft's Windows has a long history which started with the OS

called "DOS" (Disc Operating System).

Apple Macintosh is another company which offers an OS for

computers. The "Mac" is preferred by graphic designers and artists.

LINUX is a free OS. "Free" means that users don't have to pay

use it, and that programmers can modify the OS as they like.

There are also various OS for mobile telephones.