BASIC AND THE FIRST PC

Why is BASIC synonymous with personal computers today? It started in the early 1970s, when two Seattle teenagers named Bill Gates and Paul Allen worked for a computer firm. Gates and Allen were among the first hackers who spent almost every waking hour figuring out how mainframe and minicomputer operating systems worked. They had convinced a Seattle computer firm to let them work on the company's PDP-10 minicomputer to solve the company's systems problems. Their success in this project made a name for them.

Two years later, after both men had tried college, they read about the first personal computer—the Altair. The Altair, which used an Intel 8080 chip, was built by a firm called MITS. Gates and Allen called MITS and proposed to develop a version of BASIC that would run on the Altair personal computer. Because they did not have an Altair computer, Allen used that computer's specifications to develop a simulated Altair on the PDP minicomputer. With only the simulated Altair, the two developed a form of BASIC that they thought would work on the real computer. Less than two months after the original contact with MITS, the software was finished, and Gates and Allen were on a plane to Albuquerque to demonstrate their Altair BASIC for MITS. In true storybook fashion, the BASIC worked the first time it was loaded on the Altair, even though Gates and Allen had never seen one before.

After this success, Gates and Allen formed a company called Microsoft to make their version of BASIC—the rest is history. Today, Microsoft BASIC is an industry standard.

TOOLS OF THE TRADE

Just as carpenters need tools to build a house, programmers need tools to build an information system. The difference is that carpenters' tools are of a physical nature, while programmers' tools are computer languages. And just as carpenters select a particular tool to do a particular job on the house, programmers select the computer language they will use based on the type of program to be written. The question is, how do programmers choose the necessary language for an application? There are more programming languages available today than most people could learn in a lifetime, so programmers need some rules to follow in selecting a language for a particular task. This selection process can be divided into three steps: (1) determine the application to be developed, (2) identify the features the language must have in order to deal with that application, and (3) consider the practical ramifications of choosing a particular language.

In characterizing the application being developed, a programmer should consider the size and type of application and how close to the level of the machine the language must be. One language may be great for handling very large business applications but useless for controlling a machine on a second-by-second basis. Similarly, one language may be good for doing scientific computations but not very good for producing multicolor graphics.

In choosing a language to meet the needs of the application, it is best first to list the features the application requires. These can be used to rate each list of languages from which one may be chosen. Features might include the class of problems for which the language was designed, the clarity of the language syntax (grammar), the types of data that are supported, and the ease with which a program can be moved between machines.

After the programmer develops a short list of potential languages by comparing language characteristics to the features required by the application, the last step is to consider practical questions like how much support the language requires, whether the language is available or will have to be purchased, and how much knowledge of the language the programmer already has. Once these questions are answered, the list of languages will probably have been whittled down to only one or two choices.

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