Naval Tactical Data System

This could be addressed by adding inter-ship radio or flag signals as another input to the map, but the workload of moving so many bits of data was enormous.

During World War II and the immediate post-war era, major navies started studying these problems in depth, as concerns about coordinated attacks by long-range high-speed aircraft became a serious threat.

[1] What was ultimately desired was a system that could collect target information from any sensor in the fleet, use that to build a single shared picture of the battlespace, and then distribute that data accurately and automatically to all of the ships.

The data for each of these tracks, a series of voltages, could then be transmitted around the ship, and later, inter-ship transmission using pulse-code modulation.

[2] The work by the RN and RCN teams was well known to the USN starting as early as 1946, and included live demonstrations of the Canadian system on Lake Ontario.

They also built their own version of the Royal Navy's concept as the "Electronic Data System", and 20 sets were eventually produced by Motorola.

Their system also used vacuum tubes and would end up being the largest computers ever built, each occupying 20,000 square feet (1,900 m2) of floor space, weighing 150 short tons (140 t), and consuming 1.5 megawatts of electrical power.

[3] Development of computers in the mid-1950s led both by the Navy's long interest in code-breaking computers, the introduction of newer types of transistors, and the widespread introduction of core memory, reached a point where a Navy version of Air Force's SAGE air defense network was a practical possibility.

First production NTDS runs were ordered for 17 high priority ships with missiles including 10 Belknap-class cruisers under construction between 1962-67.

[5] A variety of UNIVAC embedded computers, including the first fielded version of the late 1950s, the CP-642A[6] (AN/USQ-20), typically with 30 bit words, 32K words of magnetic core or thin film memory, 16 parallel I/O channels (also 30 bits wide) connected to radars and other peripherals, and a RISC-like instruction set, were used.

The NTDS information was transmitted between ships of aircraft carrier battle groups using Collins Radio's Kineplex modems.

The ASWSC&CS allowed the development of improvements in antisubmarine warfare using digital computers, which were implemented in other ASW ship classes.