Processing Capabilities

Computer processing involves manipulating the symbols that people use to represent things. Likewise, we create and manipulate many kinds of symbols that represent the facts and concepts of our lives.

The word data is the plural form of datum which means fact. Data are facts-the raw materials of information. Data are represented by symbols, but they are not information except in a limited sense. As used in data processing, information is data arranged in an order and from that is useful to the people who receive it. That information is a relevant knowledge, produced as the output of data processing operations and acquired by people to enhance understanding and to achieve specific purposes.

The following four operations are the only ones a computer can perform, but they enable computers to carry out the data processing activities:

1. Input/output operation
2. Text manipulation and calculation operation
3. Logic/comparison operation
4. Storage and retrieval operation

Clock Speed of the Computer

Clock speed of the computer is measured in terms of Megahertz (MHz). One million cycles per second is called Megahertz. The original IBM PC operated an 8088 microprocessor at 4.77 MHz. The modern Pentium processor runs at 1GHz or above.

In addition to being very fast, computers are very accurate. The circuits in a computer have no mechanical parts to wear and malfunction. Performing their hundreds or thousands (or millions) of operations every second, these circuits can run errorless for days at a time. If the input data entering the computer are correct and if the program of instructions is reliable, then we can expect that the computer generally will produce accurate output. Perhaps we have heard the phrase, garbage-in-garbage out, or GIGO. These are the error performed by the user level, not by computer itself.

Speed and Accuracy Capabilities of a Computer

A computer works one step at a time. It can add and subtract numbers, compare letters to determine alphabetical sequence, and move and copy numbers and letters. There is nothing so difficult in these operations. What is significant is the computer's speed. The time required for computer to execute such basic operation as adding and subtracting varies from a few microseconds (millionths of a second) for small machines to 80 nanoseconds (billionths of a second) or even less for large ones. Fractions of a second is given below:

Unit of Time                                                                           Part of a Second

Millisecond (ms)                                                       One-thousandth (1/1,000)

Microsecond (µs)                                                     One-millionth (1/1,000,000)

Nanosecond (ns)                                                      One-billionth (1/1,000,000,000)

Picosecond (ps)                                                       One-trillionth (1/1,000,000,000,000)