Description
Technical Manual Change 1 (TM 9-1220-221-20P) for M18 Gun Direction Computer July 1964
This Technical Manual Change 1 for TM 9-1220-221-20P covers the M18 Gun Direction Computer and is dated July 7, 1964.
The publication is an official update to the Organizational Maintenance Repair Parts and Special Tool Lists manual issued on November 14, 1962. It is a change notice rather than the complete base manual.
Historical Significance
The M18 Gun Direction Computer, commonly known as FADAC, was one of the U.S. Army’s early field-deployable digital computers. FADAC stands for Field Artillery Digital Automatic Computer.
The M18 calculated firing data for cannon and rocket artillery using information about the firing unit, target, ammunition, and ballistic conditions. Its electronic construction used replaceable plug-in circuit boards, allowing authorized maintenance organizations to exchange assemblies rather than troubleshoot every circuit at the component level.
What This Manual Covers
Change 1 revises the organizational-maintenance repair-parts information for the M18 Gun Direction Computer.
The notice specifically:
- Adds a footnote to the original parts manual
- Identifies the authorized Table of Organization and Equipment organizations
- Establishes which organizations could stock plug-in circuit boards
- Updates the authorized quantities listed on page 4, column 6
- Limits the listed circuit boards to supporting the M18 Gun Direction Computer
The notice contains only the July 1964 revisions and supplements rather than replaces the complete TM 9-1220-221-20P base publication.
Key Features
- Official publication number: Change 1 to TM 9-1220-221-20P
- Change publication date: July 7, 1964
- Original manual date: November 14, 1962
- Equipment covered: M18 Gun Direction Computer
- Common designation: FADAC
- Publication type: official technical manual change notice
- Maintenance scope: organizational repair parts and special tools
- Specific update: authorized stockage of plug-in circuit boards
- Published by: Headquarters, Department of the Army
Why This Manual Matters
Change 1 documents how the Army controlled the distribution of replacement circuit boards for an early digital artillery computer. It provides a focused record of the organizational-maintenance and supply policies used to keep the M18 operational in the field.
The notice is also useful for completing an original November 1962 TM 9-1220-221-20P manual set and preserving the publication history of the FADAC system.
About This Manual
Published by Headquarters, Department of the Army in Washington, D.C., on July 7, 1964, this is Change 1 to TM 9-1220-221-20P.
It updates the Organizational Maintenance Repair Parts and Special Tool Lists manual for the M18 Gun Direction Computer issued on November 14, 1962. This item is the official change notice and is not the complete base publication.
Ideal For
This technical manual change is a strong fit for:
- U.S. Army technical-manual collectors
- M18 FADAC restoration projects
- Field artillery and fire-direction researchers
- Military-computer historians
- Vietnam-era artillery collections
- Collectors completing a TM 9-1220-221-20P manual set
- Military museums and reference libraries
Approx length 8", Approx width 10", Approx height .1", Approx weight .2lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item's general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
Please visit our page about order lead times here: Order Lead Times