Method for encoding and decoding characters in a message to be transmitted between a first system and a second system

摘要

A first system sends a message to a second system via a modem. A processor in the first system, in conjunction with a stored encoding algorithm, encodes the characters of the message by locating unacceptable characters (U) among the acceptable characters (A) in the message, the unacceptable characters possessing more than one meaning and triggering the execution of a function other than the intended function. A bias code (70) is selected for the acceptable characters (A) and a further bias code (75) is selected for the unacceptable characters (U). The unacceptable characters are converted into modified acceptable characters (Aʹ). The bias code, acceptable characters, further bias code, and modified acceptable characters are then transmitted. The second system interprets the bias code to mean that the acceptable characters should be accepted without alteration, but interprets the further bias code to mean that the modified acceptable characters should be re-converted into the original unacceptable characters.