By Darwyn F. Kelley
The World's First Electronic Computer
The ENIAC computer, pictured above was installed ,at Aberdeen Proving Grounds , Aberdeen, Maryland. It weighed nearly 30 tons and occupied 15,000 square feet of floor space.
ENIAC contained more than 19,000 vacuum tubes which were used to perform
5,000 additions per second. .As one might expect, making ENIAC function was a tedious task. Operators used plug boards and wires to program the desires operations and entered the numbers used in calculations by turning a series of dials until they corresponded to the correct digits.
By today's standards, ENIAC was slow, but it was 60 times faster than the mechanical differential analyzer which it replaced and at that time this was a large advance. ENIAC led the computer field during the period
1949 through 1952 when it served as the main computer workhouse for the solution of scientific problems of the Nation. It was the major instrument for the computation of all ballistic tables for the U.S. Army and Air Force.
As a Sperry Univac, Senior System Engineer, assigned to the Univac installation at the Aberdeen Proving Grounds in
1957. ENIAC was delivered to the Ballistics Research Laboratory, (BRL) in
1946, therefore I missed this installation but did have many discussions with the personnel that used to work on this first amazing computer.
It actually was not used to solve "Knotty Nuclear Problems" , but actually computed firing tables for the White Sands missile range.
BRL also had many firsts., EDVAC and ORDVAC Computers were very powerful military computers which replaced ENIAC. Around
1958/1959 BRL decided to build a very advanced Scientific Computer.
BRLESC. (BRL Electronic Scientific Computer). This was a very expensive and powerful computer but it did contain vacuum tubes at the time when all commercial computers were switching to solid state devices. This computer was made obsolete by Solid State Technology.
The next machine produced by the Eckert & Mauchly team was Binac, special-purpose computer, Only one was built. Binac embodied four important advances, however: it used serial instead of parallel logic; it was the first computer to be internally programmed; it was the first computer to use magnetic tape; and it was the first computer to use solid state elements. Internal programming eliminated the time-consuming and tedious task of changing a problem by connecting external cables.
In parallel-logic systems, if one wishes to add two 3 digit numbers, one provides three add circuits, one for each column. In a serial machine, the columns are added one at a time, sequentially. This arrangement eliminates many parts and, of course, when the number of parts goes down so does the cost.
Binac's use of Magnetic tape was limited to small reels. Small as it was, however, this 2 inch reel was the forerunner of the complex tape input and storage systems.
In part, Binac achieved the speed necessary to the successful operation of a serial machine by the use of crystal diodes instead of vacuum tubes for switches.
All sequential machines really are giant switching
networks. Vacuum tubes still were used for amplification, but this first use of crystal diodes, as long ago as
1948, foreshadowed today's all solid-state machines with their greatly increased speeds and greatly reduced size, power and cooling requirements, and costs. A solid state component uses the flow of electrons through a solid material.
After Binac, new developments came thick and fast. The memory utilized in Binac was
mercury tank memory. The design of this storage device was based on the very simple fact that an electrical pulse could be converted to a sound pulse (by means of piezo-electric quartz crystal and that this sound crystal would travel at relative low speed through a body of mercury. When it came out the other end, it could be reconverted to an electrical pulse by another crystal, amplified, and sent back into the tank. The net result was that the "bit" of information kept circulating until such time until called for by the computers circuitry. Mercury Delay Memory was also utilized in the Univac I Computer.