We are having problems with a Cherry SPOS keyboard. The cardswipe is inserting '70' (without quotes) at the end of the stream. I have been unable to find a way to eliminate this in the programming. For our application, we need to complete the stream with a carriage return ... which I also cannot get the programming to accept. The remainder of the keyboard accepts / modifies programming with no issues.

Are you sure this is not a checksum? Have you ever worked with magnetic strip readers before? I have, and usually there is a checksum appended to the data stream, unless you have configured the hardware to leave it off. In any case, the reader should still validate the checksum, although some cheap readers may leave that up to the scanning software. If that is the case, then you need to have a device driver that will deal with that cruft, and present you with either a "bad scan" error, or the correct data string.