DYSEAC
Encyclopedia
DYSEAC was the Second Standards Electronic Automatic Computer. (See SEAC
.)
DYSEAC was a first-generation computer
built by the National Bureau of Standards
for the US Army Signal Corps. It was housed in a truck, making it one of the first portable computers (perhaps the first). It went into operation in April 1954.
DYSEAC used 900 vacuum tube
s and 24,500 crystal diode
s. It had a memory
of 512 words of 45 bit
s each (plus one parity bit
), using mercury delay line memory
. Memory access time was 48-384 microseconds. The addition time was 48 microsecond
and the multiplication/division time was 2112 microseconds. These times are excluding the memory access time, which added up to approximately 1500 microseconds to those times.
SEAC (computer)
SEAC was a first-generation electronic computer, built in 1950 by the U.S. National Bureau of Standards and was initially called the National Bureau of Standards Interim Computer, because it was a small-scale computer designed to be built quickly and put into operation while the NBS waited for...
.)
DYSEAC was a first-generation computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
built by the National Bureau of Standards
National Institute of Standards and Technology
The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...
for the US Army Signal Corps. It was housed in a truck, making it one of the first portable computers (perhaps the first). It went into operation in April 1954.
DYSEAC used 900 vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s and 24,500 crystal diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
s. It had a memory
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
of 512 words of 45 bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
s each (plus one parity bit
Parity bit
A parity bit is a bit that is added to ensure that the number of bits with the value one in a set of bits is even or odd. Parity bits are used as the simplest form of error detecting code....
), using mercury delay line memory
Delay line memory
Delay line memory was a form of computer memory used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was serial-access...
. Memory access time was 48-384 microseconds. The addition time was 48 microsecond
Microsecond
A microsecond is an SI unit of time equal to one millionth of a second. Its symbol is µs.A microsecond is equal to 1000 nanoseconds or 1/1000 millisecond...
and the multiplication/division time was 2112 microseconds. These times are excluding the memory access time, which added up to approximately 1500 microseconds to those times.