I am using Caesar 5.3 and every time I try to save a file its saving as a ._A extension instead of a ".C 2" extension. I opened my file and selected the save as option to rename and the the extension ".C 2" shows up in the box, but it stilll saves as a ._A file once I'm finished.

The Piping Input processor always saves an _A file, you can't change this - don't try to rename this file, it won't work. When you exit CAESAR II, or change jobs from within CAESAR II, the current job and all of the associated files (there are more than just the _A file) are zipped up into the ".C 2" archive.

When you work on the job again, the ".C 2" archive is exploded into all of the job's component files.