Tech Innovations
The Atanasoff-Berry Computer

The Atanasoff Berry Computer, or ABC, was a remarkable innovation for a number of reasons. Characteristics of modern computers trace their roots directly to the ABC, which sits at the top of the family tree of computing.

Particular breakthroughs first found in the ABC include:


Electronic regenerative memory -

Today's RAM memory chips employ the same concepts first employed by the ABC. While the computer is on, the memory is refreshed. Atanasoff called this "jogging" the memory. The use of the word "memory" itself in relation to computers is also credited to Atanasoff.

Base 2, or binary, storage -

In other computing devices, it was customary to use the base-10 system that humans use for working with numbers. Using a base-2 system was ingenious because it took advantage of the "on-off" nature of vacuum-tube electronics and punched cards.

Boolean Logic -

Today, using the "ANDs" and "ORs" of Boolean logic for computing seems natural. In the 1930s, however, primitive mechanical calculators were using decimal gears to manually crank out results. By going with base-2 arithmetic, Atanasoff made use of Boolean logic for computing possible.

Separation of memory and computing functions -

In essence, all of the primary components found in today's computers -- CPU, storage devices, and memory -- were present in the ABC for the first time. The add-subtract circuits found in the ABC were modular and could be popped out and replaced much in the same way a CPU chip can be today. The memory storage in the ABC -- a total of 3.2 kilobits -- was completely separate from the add-subtract units.

Global system clock-

Today's computers are often measured in terms of their "gigahertz" clock speeds. That feature of a system clock for the computer to time its operations was first introduced in the ABC, allowing more reliable and repeatable operations.

Parallel processing-

Some people think that parallel processing -- the ability for a computer to do more than one thing at the same time -- is a fairly recent idea. But the ABC was far ahead of its time in this respect. It did 30 operations at once, using a technology that today we call SIMD (pronounced "sim-dee"), for Single-Instruction Multiple-Data parallel computing. Parallel processing is now universal in the design of computers from PCs to the largest mainframes.

Any one of these innovations would have been remarkable for the late 1930s. Atanasoff's breakthrough in Rock Island was to decide upon all four of these concepts in one evening - essentially the conception of the modern family of computers that we enjoy today.




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