FADAC M18TACFIRE communications terminal box at Fort Sill
M1: This was used by seacoast artillery for major-caliber seacoast guns. It computed continuous firing data for a battery of two guns that were separated by not more than 1,000 feet (300 m). It utilised the same type of input data furnished by a range section with the then-current (1940) types of position-finding and fire-control equipment.
M3: This was used in conjunction with the M9 and M10 directors to compute all required firing data, i.e. azimuth, elevation and fuze time. The computations were made continuously, so that the gun was at all times correctly pointed and the fuze correctly timed for firing at any instant. The computer was mounted in the M13 or M14 director trailer.
M4: This was identical to the M3 except for some mechanisms and parts which were altered to allow for different ammunition being used.
M8: This was an electronic computer (using vacuum tube technology) built by Bell Labs and used by coast artillery with medium-caliber guns (up to 8 inches or 200 millimetres). It made the following corrections: wind, drift, Earth's rotation, muzzle velocity, air density, height of site and spot corrections.
M9: This was identical to the M8 except for some mechanisms and parts which were altered to accommodate anti-aircraft ammunition and guns.
M10: A ballistics computer, part of the M38 fire control system, for Skysweeper anti-aircraft guns.
The battery computer system (BCS) AN/GYK-29 was a computer used by the United States Army for computing artillery fire mission data. It replaced the FADAC and was small enough to fit into the HMMWV combat vehicle.
The AN/GSG-10 TACFIRE system automated field artillery command and control functions. It was composed of computers and remote devices such as the variable format message entry device (VFMED), the digital message device (DMD) and the Firefinder field artillery target acquisition radar system linked by digital communications using existing radio and wire communications equipment. Later in its service life, it also linked with the battery computer system (BCS) which had more advanced targeting algorithms.
The last TACFIRE fielding was completed during 1987. Replacement of TACFIRE equipment began during 1994.
TACFIRE used the AN/GYK-12, a second-generation mainframe computer developed primarily by Litton Industries for Army divisional field artillery (DIVARTY) units. It had two configurations, division and battalion level, housed in mobile command shelters. Field artillery brigades also use the division configuration.
Components of the system were identified using acronyms:
The AFATDS is the "Fires XXI" computer system for both tactical and technical fire control. It replaced both BCS (for technical fire solutions) and IFSAS/L-TACFIRE (for tactical fire control) systems in U.S. Field Artillery organizations, as well as in maneuver fire support elements at the battalion level and higher. As of 2009, the U.S. Army was transitioning from a version based on a Sun MicrosystemsSPARC computer running the Linux kernel to a version based on laptop computers running the Microsoft Windows operating system.
Surviving examples
One reason for a lack of surviving examples of early units was the use of radium on the dials. As a result they were classified as hazardous waste and were disposed of by the United States Department of Energy. Currently there is one surviving example of FADAC at the Fort Sill artillery museum.[8]
^Lieutenant Albert R. Milavec.
"On FADAC Maintenance"Archived 2013-02-26 at the Wayback Machine.
p. 32 of
"Artillery Trends" May 1968.
"The FADAC is an all-transistorized, stored-program, general purpose digital computer ...
Weighing approximately 200 pounds ...
the FADAC components utilize approximately 1,600 transistors, 9,000 diodes, 6,000 resistors,
500 capacitors, and many other switches, transformers, and neon lamps."
