The Fifth Generation computer should perhaps more aptly be called the second generation computer. The first four generations were marked by improvements in components - from vacuum tubes in the first generation to very-large-scale integrated circuits in the fourth. But the basic design of all four generations was the same - the computers essentially carried out one instruction at a time and were mainly designed to do numerical calculations.

The Fifth Generation is intended to handle symbols, not numbers. And it will do many things at once, much like the human brain.

There are four parts to the project.

One part is the development of technology to handle and manage vast amounts of data and knowledge. A machine diagnosing diseases must have a storehouse of facts about anatomy, disease symptoms and testing methods. Moreover, it must be able to retrieve the necessary knowledge quickly when needed.

The project has already developed a specialized machine for this purpose, which it calls the relational database machine.

Developing Reasoning Ability

The second part of the project is the inference part, which uses the knowledge to reach conclusions. If the computer is informed that a trout is a fish and that fish live in water, then the computer must be able to conclude that trout live in water.

The institute has developed a computer, known as the personal sequential inference machine, that can do such logical reasoning. While most computers are measured in how many arithmetical operations they perform each second, this machine is measured in LIPS, or logical inferences per second.

The inference machine operates on a version of the computer language known as Prolog, which is designed for logical inferences. The institute is now writing the basic software, or operating system for the machine. After that task is done, the inference machine will be used by researchers as a tool to write programs for other parts of the project.