Trados TTX files may be legacy files, unfortunately they still abound. The good thing is that you can process them in CafeTran. However, you should keep a few things in mind:
CT correctly considers the files to be "projects" rather than documents. This came as a complete surprise to me when I first wanted to change the settings in the Project File. Instead of the usual interface, I got this:
No way I could make any changes.
The next thing is that you should ask for "presegmented" TTX files, or you should presegment them yourself. The reason for that is not clear to me, since the files in the project have already been presegmented. However, if you don't take that extra step, you may end up with untranslated segments that you are not aware of, but the client will be. You can presegment the files yourself using a demo version of Trados (under Windows, I'm afraid).
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Nelson Laterman describes the process very clearly on his site, so there's no need for me to repeat it.
The problem with formats like TTX is, that there are no empty target segments. If there's a perfect match, you will see it in the target segment, if not, you will see the source text in the target segment. Very annoying, also because your memories won't make any suggestions.
I was going to mention this on my Wish List, but I made the mistake of mentioning the problem to Igor first. He instantly implemented a solution for it. For reference only, I will mention it on the Wish List anyway. Igor added the option to remove the target segments
(see the first screenshot above). A great option, depending on the number of perfect matches in the file and of whether or not the client sent you a TM. In the latter case, you can use the option without having to worry about a thing. The perfect matches will show up, although you will have to insert any tags. If you don't have a TM at your disposal, you're in trouble. You will have to decide whether or not to use the new option. I was lucky. Most files were very short, so I went through them, and added the perfect matches to the memory before removing all target segments.
(see the first screenshot above). A great option, depending on the number of perfect matches in the file and of whether or not the client sent you a TM. In the latter case, you can use the option without having to worry about a thing. The perfect matches will show up, although you will have to insert any tags. If you don't have a TM at your disposal, you're in trouble. You will have to decide whether or not to use the new option. I was lucky. Most files were very short, so I went through them, and added the perfect matches to the memory before removing all target segments.
I'm afraid I didn't even try it, but since TTX files are project files, I don't think you can import them all in one go. I don't even think you import them, you "open" them. Please correct me if I'm wrong. When I started, I wrote down which TTX files I processed. I found out soon enough that that isn't necessary.
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As you can see, the processed/translated files are shown as with different icon.