Applications of personal computers

As personal computers and workstations have become less expensive and more powerful, their numbers have increased phenomenally in offices, schools, and homes. There are many application programs that individual users can run. Document preparation, accounting, simple database management, video games, automated design of products, and education are some typical ex­amples. Being more powerful than desktop or laptop computers, workstations tend to be used more often for solving scientific and engineering problems. The following are some of the most widely used application programs in offices and homes.

Text-editing programs. Letters, reports, and documents can be easily prepared on personal computers, because the user can see on the monitor what the text will look like when printed (abbreviated as WYSIWYG, which stands for "what you see is what you get" and is pronounced "wizzy-wig"). Programs are available that check spelling and grammar before printing. Because of progress in laser printer technology, text printed by a laser printer is of typeset quality.

Desktop publishing programs. Desktop publishing is the creation of pages for publication using personal com­puters. Utilizing programs for this purpose, one can easily draw pictures using a mouse as a pointer on the monitor of the computer. Text can be easily mixed with the pictures, tables, and equations placed at desired locations.

Spreadsheet programs. Spreadsheet programs are the most popular programs for business calculations done on personal computers. They allow the user to enter columns and rows of numbers. The user can define a formula relating these columns and rows, and then the results are automatically calculated as numbers are entered. When changes in some entries are made, the program recalculates the results based on this formula.

MUSIC AND SPEECH SYNTHESIS

The designers of early computers were not interested in using them to produce sound. Now, even the smallest microcomputers have the capability of produc­ing primitive sounds, such as beeping when a program needs to attract the attention of a user. Music and speech, however, are not primitive sounds, and peripheral devices usually must be attached to a computer to produce them.

Music

A musician may use a computer during the composition process to hear immediately how a work sounds. The computer can produce the music as it would sound coming from a piano, a guitar, or from a piano and a guitar together. The composer may change a note or series of notes and have the computer play it again to hear the improvement. Alternately, a computer may be used to generate music in its own right. That is, the computer may be considered an instrument worthy of listening to like any musical instrument.

Speech

Generation of speech by a computer is much more difficult than is the generation of music, because sound patterns in speech are more complex. In recent years, however, much progress has been made in this area. In some countries there are microwave ovens that give directions by "speaking." Some grocery store registers now automatically read the coded price from a product, and a computer-generated voice tells you the price. Some coin-operated tele­phones use computer-generated voice to tell you how much to pay for a call. Computer-generated voice is also useful in any situation where text or visual presentation of information will not suffice, such as when the person cannot read, or must be looking at something other than the computer display.