The AN/USQ-20, or CP-642 or

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 s ...

(NTDS), was designed as a more reliable replacement for the Seymour Cray-designed

AN/USQ-17 The AN/USQ-17 or Naval Tactical Data System (NTDS) computer referred to in Sperry Rand documents as the Univac M-460, was Seymour Cray's last design for UNIVAC. UNIVAC later released a commercial version, the UNIVAC 490. That system was later upgr ...

with the same

instruction set In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, s ...

. The first batch of 17 computers were delivered to the Navy starting in early 1961. A version of the AN/USQ-20 for use by the other military services and

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

was designated the UNIVAC 1206. Another version, designated the G-40, replaced the vacuum tube UNIVAC 1104 in the

BOMARC Missile Program The Boeing CIM-10 Bomarc ("Boeing Michigan Aeronautical Research Center") (IM-99 Weapon System prior to September 1962) was a supersonic ramjet powered long-range surface-to-air missile (SAM) used during the Cold War for the air defense of Nor ...

. In accordance with the

Joint Electronics Type Designation System The Joint Electronics Type Designation System (JETDS), which was previously known as the Joint Army-Navy Nomenclature System (AN System. JAN) and the Joint Communications-Electronics Nomenclature System, is a method developed by the U.S. War Depa ...

(JETDS), the "''AN/USQ-20''" designation represents the 20th design of an Army-Navy

electronic device Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other electrically charged particles. It is a subfield of physics and ...

for general utility special combination equipment. The JETDS system also now is used to name all

Department of Defense The United States Department of Defense (DoD, USDOD, or DOD) is an executive department of the U.S. federal government charged with coordinating and supervising the six U.S. armed services: the Army, Navy, Marines, Air Force, Space Force, ...

electronic systems.

Technical

The machine was the size and shape of an old-fashioned double-door

refrigerator A refrigerator, commonly shortened to fridge, is a commercial and home appliance consisting of a thermal insulation, thermally insulated compartment and a heat pump (mechanical, electronic or chemical) that transfers heat from its inside to ...

, about six feet tall (roughly 1.80 meters). Instructions were represented as 30-bit

word A word is a basic element of language that carries semantics, meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguist ...

s 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 words. This allowed for five 6-bit

alphanumeric Alphanumericals or alphanumeric characters are any collection of number characters and letters in a certain language. Sometimes such characters may be mistaken one for the other. Merriam-Webster suggests that the term "alphanumeric" may often ...

characters per word. The main memory was 32,768 words of

core memory Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (laboratory), a highly specialized shared research resource * Core (manufacturing), used in casting and molding * Core (optical fiber), ...

. 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-onl ...

s were: *One 30-bit arithmetic (A) register. *A contiguous 30-bit Q register (total of 60 bits for the result of multiplication or the dividend in division). *Seven 15-bit index (B) registers (note: register B0 is always zero).

References

{{reflist

External links

UNIVAC-NTDS: UNIVAC 1206, AN/USQ-20
– From the Antique Computer website UNIVAC hardware Transistorized computers Military computers Avionics computers Military electronics of the United States

Technical

See also

References

External links