The Atanasoff-Berry Computer In Operation

Summary

This video demonstrates the Atanasoff-Berry Computer (ABC), the first electronic digital and parallel computer, built in the late 1930s and early 1940s. Through a hands-on example, the ABC is shown solving a set of equations using punch cards, binary logic, and dynamic memory. The process includes steps like data entry, conversion to binary, and variable elimination to find solutions for a system of equations. Though slow by modern standards, the ABC laid the foundation for future computing, showcasing binary logic, dynamic memory, and parallel processing.

Takeaways

• 😀 The Atanasoff-Berry Computer (ABC) was the first electronic digital computer, built at Iowa State between 1939 and 1942.
• 😀 This replica of the ABC was completed in 1997 and demonstrates its use in solving equations.
• 😀 The ABC is a parallel computer, with modular vacuum tube assemblies performing arithmetic calculations for one number at a time.
• 😀 It was the first computer to use binary digits (bits) to store numbers, with 3,000 bits of storage capacity, equivalent to a third of a kilobyte.
• 😀 The ABC can hold two equations at once, one on each of its memory drums, and it works with binary data rather than decimal.
• 😀 Data input into the ABC is done through punch cards, as there was no keyboard, and it uses a base 2 conversion drum for binary data.
• 😀 The ABC uses dynamic memory with capacitors inside rotating drums that store voltage to represent bits, refreshed once per second.
• 😀 The system’s speed is limited by the time taken for input and output, with each decimal number taking about 1 second to read in.
• 😀 The computer solves systems of equations by eliminating variables step-by-step, which reduces the complexity of solving larger systems.
• 😀 The ABC’s methods laid the foundation for solving larger systems of equations, which was difficult to do by hand before its invention.

Q & A

What was the Atanasoff-Berry Computer (ABC)?

The ABC was the first electronic digital computer, built at Iowa State between 1939 and 1942. It was also the first parallel computer, using binary digits (bits) to store numbers and solve systems of equations.

How does the ABC differ from modern computers in terms of memory and processing?

The ABC used a memory system based on rotating drums with capacitors to store bits, whereas modern computers use static memory like RAM. The ABC performed arithmetic operations in parallel, but at much slower speeds compared to modern computers.

How were equations entered into the ABC for solving?

Data was entered into the ABC using punch cards. Each punch card represented numbers in decimal, which were then converted to binary before being processed by the machine.

What were the limitations of the ABC when solving equations?

The ABC had limitations in terms of speed and precision. For example, it would take 25 hours to solve a set of 29 equations and 29 unknowns. Additionally, it only supported whole numbers and lacked floating-point arithmetic.

What was the role of the base 10 conversion drum in the ABC?

The base 10 conversion drum was used to convert decimal numbers entered from punch cards into binary, which the ABC used for processing and solving equations.

How did the ABC handle negative numbers?

The ABC used a method where a zero was typed as the first digit of a number to indicate it was negative. The absence of a zero indicated the number was positive.

How did the ABC perform arithmetic operations?

The ABC used vacuum tube assemblies to perform arithmetic operations in parallel. It processed numbers by adding or subtracting bits from memory using a clock-synchronized motor to rotate the memory drums.

What was the speed of the ABC compared to modern computers?

The ABC was much slower than modern computers. For example, reading a decimal from a punch card took 1 second, and solving two equations took about 6 minutes. Modern computers are over a trillion times faster.

Why did John Atanasoff and Clifford Berry invent the ABC?

Atanasoff and Berry invented the ABC to solve complex systems of equations in physics, statistics, and mechanics. The limitations of manual calculation in these fields motivated the development of the machine.

What was the role of the dynamic memory in the ABC?

The dynamic memory in the ABC was stored on rotating drums, with capacitors representing each bit. The memory had to be refreshed once per second to retain data and avoid fading.