Navy Tactical Data System

Sperry Univac Defense Systems, United States

The Navy Tactical Data System (NTDS) was an early transistorized military fire control computer. Computer pioneer Seymour Cray designed the machine in 1957 while at Remington Rand Univac, just prior to joining Control Data Corporation.

Computer History Museum in Mountain View, California


The webmaster Chuck White at the Computer History Museum in Mountain View, California, November 24, 2006


Computer History Museum in Mountain View, California


Computer History Museum NTDS Exhibit in Mountain View, California, photo taken by Chuck White January 12, 2012 - Note: USS KING stencilled next to red light

Sign on display board next to NTDS unit says:

READY, AIM, FIRE. That command seems simple. Yet the “aim” part can be challenging. Calculating the trajectory of high-speed projectiles, and hitting moving targets, demands complex real-time calculations. Ballistics control was a perfect challenge for real-time computing. Solutions began with mechanical analog sustems, shifting later to electronic digital systems, and then digital integrated circuits, both for military applications and for space exploration.

This armored computer was extremely reliable in hazardous environments and could control battleship radar and weapons systems in real-time. Multiple computers could communicate with each other to form a cooperative chain of machines. Over the next three decades, the NTDS served as the basis for an entire family of shipboard command and control computers.

Technical Specifications
Word Length30 Bits
Speed9.6 Microsecond add time
Primary Memory36,768 words core memory (3.6 microseconds access time).
Secondary MemoryMagnetic drums and magnetic tape
Instruction Set62 30-bit, single address instructions
ArchitectureParallel, binary, fixed point arithmetic. 7 index registers, 1 accumulator register, 1 free register
Technology10,702 transistors
Input and OutputPunched cards, paper tape, CRT
Size58.6 cubic feet, 2,320 pounds, 2.5 kW
SoftwareCS-1 compiler
Development HistoryDeveloped under contract for the Navy Tactical Data Systems (NTDS) by the Saint Paul division of Remington-Rand Univac. Seymour Cray was the primary logic and circuit designer
Production HistoryThe first units were delivered in 1958. Later commercially available as the UNIVAC 1206
UseReal-time tactical analysis, display, and control of weapons

Further reading can be found here at the IEEE Global History website Wiki