Naval Tactical Data System
Naval Tactical Data System (NTDS) was a computerized information processing system developed by the United States Navy in the 1950s and first deployed in the early 1960s for use in combat ships. It took reports from multiple sensors on different sh ...
(NTDS) computer referred to in
Sperry Rand
Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs ...
documents as the Univac M-460, was
Seymour Cray
Seymour Roger Cray (September 28, 1925 – October 5, 1996 ) was an American
UNIVAC
UNIVAC (Universal Automatic Computer) was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company an ...
. UNIVAC later released a commercial version, the
UNIVAC 490
UNIVAC (Universal Automatic Computer) was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company and ...
and that system was later upgraded to a multiprocessor configuration as the 494.
Overview
The machine was the size and shape of a refrigerator, about four feet high (roughly 1.20 meters), with a hinged lid for access. However, shortly after completing the prototype design Cray left to join
Control Data Corporation
Control Data Corporation (CDC) was a mainframe and supercomputer firm. CDC was one of the nine major United States computer companies through most of the 1960s; the others were IBM, Burroughs Corporation, DEC, NCR, General Electric, Honeywel ...
. When the Navy awarded Sperry Rand a US$50 million contract to build the AN/USQ-17, Univac engineers redesigned the entire machine from scratch using silicon transistors (retaining the
instruction set
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ' ...
so that programs developed for the original machine would still run on the new one).
As part of the redesign it was decided to improve access, and the second version was designed to stand upright, like an old fashioned double-door
refrigerator
A refrigerator, colloquially fridge, is a commercial and home appliance consisting of a thermally insulated compartment and a heat pump (mechanical, electronic or chemical) that transfers heat from its inside to its external environment so th ...
, about six feet tall (roughly 1.80 m). This new design was designated the
AN/USQ-20
The AN/USQ-20, or CP-642 or Naval Tactical Data System (NTDS), was designed as a more reliable replacement for the Seymour Cray-designed AN/USQ-17 with the same instruction set. The first batch of 17 computers were delivered to the Navy sta ...
.
Instructions were represented as 30-bit words, in the following format:
f 6 bits function code
j 3 bits jump condition designator
k 3 bits partial word designator
b 3 bits which index register to use
y 15 bits operand address in memory
Numbers were represented as 30-bit
word
A word is a basic element of language that carries an semantics, objective or pragmatics, practical semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of w ...
s, this allowed for five 6-bit alphanumeric characters per word.
The main memory was 32,768 = 32 K words of
core memory
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the centra ...
.
The available
processor register
A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only. ...
s were:
*One 30-bit accumulator (A).
*One 30-bit Q register (combined with A to give a total of 60 bits for the result of multiplication or the dividend in division).
*Seven 15-bit
index register
An index register in a computer's CPU is a processor register (or an assigned memory location) used for pointing to operand addresses during the run of a program. It is useful for stepping through strings and arrays. It can also be used for hol ...
s (B1–B7).
The instruction format defined for the AN/USQ-17 marked the beginning of an instruction set which would be carried on, with many changes along the way, into later UNIVAC computers including the
UNIVAC 1100/2200 series
The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Ser ...
which is still in use .
First delivery of NTDS and related U.S. Navy computers
AN/USQ-20
The AN/USQ-20, or CP-642 or Naval Tactical Data System (NTDS), was designed as a more reliable replacement for the Seymour Cray-designed AN/USQ-17 with the same instruction set. The first batch of 17 computers were delivered to the Navy sta ...
AN/UYK-20
The AN/UYK-20 "Data Processing Set" was a ruggedized small computer manufactured by Univac and used by the United States Navy for small and medium-sized shipboard and shore systems built in the 1970s. It featured non-volatile magnetic core memory ...
, 16 bit, 1973
*
AN/AYK-14
The AN/AYK-14(V) is a family of computers for use in military weapons systems. It is a general-purpose 16-bit microprogrammed computer, intended for airborne vehicles and missions. Its modular design provides for common firmware and support softwar ...
List of UNIVAC products
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College, an undergraduate division of the Jewish Theological Seminary of America
* SC Germania List, German rugby union ...
*
History of computing hardware
The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers. Before the 20th century, most calculations were done by humans.
The first aids to computation were purely mechan ...