Editing SIGABA (section)

==Interoperability with Allied counterparts==
The need for cooperation among US, British, and Canadian forces in carrying out joint military operations against Axis forces gave rise to the need for a cipher  system that could be used by all Allied forces. This functionality was achieved in three different ways. Firstly, the ECM Adapter (CSP 1000), which could be [[retrofitting|retrofitted]] on Allied cipher machines, was produced at the Washington Naval Yard ECM Repair Shop. A total of 3,500 adapters were produced.<ref name="NSA"/> The second method was to adapt the SIGABA for interoperation with a modified British machine, the [[Typex]]. The common machine was known as the [[Combined Cipher Machine]] (CCM), and was used from November 1943.<ref name="Sterling"/> Because of the high cost of production, only 631 CCMs were made. The third way was the most common and most cost-effective. It was the "X" Adapter manufactured by the [[Teletype Corporation]] in Chicago. A total of 4,500 of these adapters were installed at depot-level maintenance facilities.<ref name="NSA"/>