Combined Document Exploitation Center (CDEC) Collection

Accessing the CDEC Collection in the Virtual Vietnam Archive

To search the the CDEC Collection in the Virtual Vietnam Archive, click "CDEC Search".

About the CDEC Collection

The Combined Document Exploitation Center was created by the US Army in 1966 to handle the increase in materials captured from North Vietnamese and Vietcong forces. A wide variety of types of documents were captured and kept, including diaries, letters, reports and photographs. CDEC summarized and translated documents that contained valuable intelligence. Many thousands of pages of non-useful materials were destroyed. Each kept document was assigned a log number consisting of the two digit month, followed by the document number, and finally the two digit year. CDEC then filmed the files captured each day, in the order in which they were captured, on movie stock with an 8-bit coding on the soundtrack. This coding is the only real "index" to the CDEC collection. CDEC used a Filesearch machine to access the filmed items. In theory the Filesearch machine could be used to search the entire collection of filmed documents for requested subjects.

Since the end of the war, all the Filesearch machines have become either lost or unusable, making the 8-bit coding useless for researchers. Following the war, over 100 reels of the Filesearch film were transferred to the National Archives. The National Archives has since copied the materials onto 954 reels of 35mm microfilm. Reels 2-914 (there is no reel 1) contain the captured documents and summaries. Reels 915-955 include monthly CDEC bulletins. The collection was declassified in 1979, and copies of the entire microfilm collection are available to researchers at numerous libraries and archives around the country, including The Vietnam Center and Sam Johnson Vietnam Archive.

In cooperation with the Defense Prisoner of War Missing Personnel Office, The Vietnam Center and Sam Johnson Vietnam Archive commissioned the development of software to crack the 8-bit pattern coding of the CDEC microfilm. The software produced text files containing the information in the coding, which was then imported into the Virtual Vietnam Archive, making the entire CDEC collection searchable.

Searching the CDEC Collection

The entire CDEC collection has been digitized and the collection is searchable in the Virtual Vietnam Archive using the field indexes decoded from the microfilm. However, there are two important considerations to keep in mind when searching the CDEC collection. First, the terms used in the field indexes are terms deemed useful for military searching purposes during the Vietnam conflict. These terms do not necessarily correlate to what researchers today might find to be useful search terms for their purposes. Secondly, it should be noted that the decoded indexes are not infallible. Implementation errors made by military officials when the indexes were originally coded or interpretation errors made by the software in decoding the indexes have led to the occasional instance of a search term being misapplied. Keep this information in mind when searching the CDEC collection.

Citations

Information about the CDEC collection on this page came from the following sources:

• POW Network: CDEC Description
• University of Massachusetts at Boston Joseph P. Healey Library: Combined Document Exploitation Center, Saigon: Captured documents from the Vietnam War, 1966-1973