EBCDIC 6-Bit

EBCDIC 6-Bit, or BCD six-bit codes, can refer to several variations on character codes six bits in length that derive from Binary Coded Decimal (BCD), which was expanded by IBM into a larger character set. The 6-bit versions add uppercase letters and a few symbols in addition to numbers; normal EBCDIC is an 8-bit code with a number of additional code points allowing both upper and lower case and more punctuation and other characters.

Links

 * Wikipedia article on 6-bit character codes