问题
What is an example of a character encoding which is not compatible with ASCII and why isn't it?
Also, what are other encoding which have upward compatibility with ASCII (except UTF and ISO8859, which I already know) and for what reason?
回答1:
There are EBCDIC-based encodings that are not compatible with ASCII. For example, I recently encountered an email that was encoded using CP1026, aka EBCDIC 1026. If you look at its character table, letters and numbers are encoded at very different offsets than in ASCII. This was throwing off my email parser particularly because LF is encoded as 0x25 instead of as 0x0A in ASCII.
来源：https://stackoverflow.com/questions/32186483/ascii-compatibles-and-not-compatibles-characters-encoding