EDVAC

This was a very large computer.

It was built in a school in the United States. Two men helped design it. It could do math very fast.

The machine used many small parts to work. It had many glass tubes inside. It also used many tiny parts called diodes.

This computer could save its own instructions. This helped it work better. It was a new way to build machines.

It worked for many years. It helped people at a lab. It was a very important machine.

The EDVAC was one of the first electronic computers.

Two men named John Mauchly and J. Presper Eckert designed it. They worked at a school in Pennsylvania. The machine was built for the U.S. Army.

This computer was special because of its design. It was a stored-program computer. This means it kept its instructions in its own memory. A man named John von Neumann wrote about this idea. Today, many computers use this same way of working.

The EDVAC was very big and used much power. It had 5,937 vacuum tubes. It also had 12,000 diodes. These are tiny parts that help electricity flow. The machine used binary math. This means it used a system of ones and zeros. It could add, subtract, and multiply numbers. It could even do division. It used mercury lines for its memory. These lines helped it store data. The machine worked at a lab until 1962. It was a very important step for science.

The EDVAC was a very important early electronic computer.

It was built at the Moore School of Electrical Engineering in Pennsylvania. This machine was a successor to an older computer called the ENIAC. While the ENIAC used a decimal system, the EDVAC used binary. Binary is a system based on ones and zeros. This change helped the machine work in a new way. It was designed to be a stored-program computer. This meant it could keep its instructions in its own memory. This idea changed how all computers work today.

How the EDVAC worked was quite complex. It was a binary serial computer. This means it processed information in a specific order. The machine could perform addition, subtraction, and multiplication automatically. It could also do programmed division and automatic checking.

The computer used a special memory called ultrasonic serial memory. This memory used 64 mercury acoustic delay lines to store data. It had a capacity of 1,024 words. Each word was 44 bits long. This gave it a memory of about 5.6 kilobytes.

Many smart people helped create this machine. John Mauchly and J. Presper Eckert first proposed the idea in August 1945. They were the same men who invented the ENIAC. John von Neumann also helped as a consultant. He wrote a famous report about the EDVAC in 1945. This report explained the stored-program concept. Because of his work, many people call this the Von Neumann architecture. This design is used by most computers made today.

The EDVAC was a huge and powerful machine. It used 5,937 vacuum tubes and 12,000 diodes. It also used 56 kilowatts of power. The computer covered 490 square feet of floor space. It was delivered to the Ballistic Research Laboratory in 1949. An initial contract to build it was signed in April 1946. That contract started with a budget of $100,000. However, the final cost was just under $500,000. It took thirty people to run one eight-hour shift.

You can think of the EDVAC as a very early ancestor of your tablet or laptop. Even though it was much slower, it used similar ideas. For example, the EDVAC took 864 microseconds to add numbers. It took 2,900 microseconds to multiply them. Today, our computers do these things much faster. The EDVAC also had upgrades over time. In 1954, it received punch-card tools. In 1955, it got extra memory using a magnetic drum. It ran at the laboratory until 1962.

The EDVAC, or Electronic Discrete Variable Automatic Computer, was a landmark in the history of computing.

It was one of the earliest electronic computers ever built. Developed at the Moore School of Electrical Engineering at the University of Pennsylvania, it served as a successor to the ENIAC. While the ENIAC used a decimal system, the EDVAC utilized a binary system. This means it operated using base-two logic rather than base-ten. This shift allowed the machine to function as a stored-program computer. This capability changed the way machines processed information forever.

The machine functioned as a binary serial computer. It could perform several arithmetic operations automatically, such as addition, subtraction, and multiplication. It also handled programmed division and included automatic checking features.

To store information, it used an ultrasonic serial memory. This system relied on 64 mercury acoustic delay lines to hold data. The memory had a capacity of 1,024 words, with each word consisting of 44 bits. In modern terms, this provided a memory capacity of approximately 5.6 kilobytes.

The physical components of the EDVAC were massive and complex. The computer contained 5,937 vacuum tubes and 12,000 diodes. It required 56 kilowatts of power to operate. The machine occupied 490 square feet of floor space. To keep the system running, a full complement of thirty people was needed for every eight-hour shift. The hardware also included a magnetic tape reader-recorder and a control unit equipped with an oscilloscope. A dispatcher unit sent instructions from the control and memory to other parts of the system.

Many significant figures contributed to the development of the EDVAC. John Mauchly and J. Presper Eckert, the inventors of the ENIAC, proposed the construction in August 1944. They were joined by John von Neumann, who served in a consulting role. Between February and June 1945, von Neumann wrote the "First Draft of a Report on the EDVAC." This document summarized the logical design developments of the machine. The project faced challenges when Eckert and Mauchly left the Moore School in March 1946. They did this because of a disagreement over a new university patent policy. They subsequently founded the Electronic Control Company in Philadelphia.

Financial details show how much the project grew during its development. An initial contract was signed in April 1946 with a budget of US$100,000. However, the final cost of the EDVAC reached just under $500,000. The machine was eventually delivered to the Ballistic Research Laboratory in 1949. It began limited operations in 1951 after engineers solved various technical problems. By 1952, the computer was running for several hours each day. By 1957, its usage increased to over 20 hours per day, with an average error-free runtime of 8 hours.

Speed and precision were central to the EDVAC's performance. The average time for an addition operation was 864 microseconds. This allowed for about 1,160 operations per second. Multiplication was slower, taking an average of 2,900 microseconds. This resulted in about 340 operations per second. The time required for an operation depended on the memory access time. This time varied based on the memory address and the current point in the serial memory's recirculation cycle. The machine could also perform floating-point arithmetic using specific bit allocations for the mantissa and the power of two.

The legacy of the EDVAC is found in the Von Neumann architecture. This term describes the stored-program concept where instructions are kept in the same memory as the data. John von Neumann's report proposed this major enhancement to the design. This architecture was later used by the EDSAC at Cambridge and the Manchester Baby. Most modern computers follow this design today. Computers that keep programs and data in separate memories are instead called the Harvard architecture. The EDVAC remained in service until 1962, when it was finally replaced by the BRLESC.