Communicating With The Computer
In order for us to communicate with our computers, we must have a way of providing information to the computer and a way of receiving information from the computer.
  • When the first computers were developed, we had to communicate with them by reading and interpreting a row of lights to understand information provided by the computer.

  • We gave the computer information (Programs and data) by manipulating rows of switches in a certain coded format. In modern times, there are several devices available to accomplish the same tasks that are much easier to use.
Since then, the way we communicate with computers has improved tremendously. Sweeping changes to computers and operating software have made it much easier to input and extract information.

Since 1986 we have seen processor chips developed such as the 80386, 80486, and the Pentium. Each of these chips has provided major increases to the computing power and the ease of communication with personal computers

Storage Devices -One of the methods we use in modern times is to input stored data or programs from several different types of storage devices.

In an office environment people use their computers to create, edit, review, and organize paper documents. (Example - Letters, reports, etc.)

When we want to permanently store this type information for future use, we can use these storage devices. Unlike the electronic memory in computers (RAM), storage devices store data permanently.

Most computers have at least two or more devices capable of storing data permanently. These devices use magnetic encoding as a storage method. Some of these devices are:

  • Floppy Disks - Flexible removable storage disks.

  • Hard Disks - Non-removable high capacity storage disks.

  • Magnetic Tapes - Removable Cassette tapes similar to music tapes.

How is data Stored ?
How is data stored? Data is stored on these devices one character at a time. Each character (letter, number, or special graphic) of information is stored in an encoded format called the American Standard Code For Information Interchange or (ASCII). The ASCII coded character is broken down as follows:
  • One (1) character = (1) Byte of data.
  • One (1) Byte = 8 electronic components called bits.
  • One (1) Kilobyte = 1,024 Bytes (referred to as 1K)
  • One (1) Megabyte = 1,024,000 (1024k) bytes (referred to as 1MB)
As a letter created by you is saved to one of these storage devices, each character is written one bit at a time. Each bit of a character in the ASCII code is turned either on or off (like a light bulb) in a specific pattern to form the code. The capacity or number of bytes that can be written to it before the device is full determines the size of a storage device.

Input devices - Input devices are the parts of the computer that directly react with the outside world. Input devices are used to put data into the computer. They are basically the same as the senses (eyes, Nose, ears, etc.) you use to feed information into your brain

Output devices - Output devices also directly react with the outside world. Output devices are used to get data from the computer. The chart below shows a breakdown of some of the more common hardware devices found in the average computer.