The American Standard Code for Information Interchange (ASCII), also known as ANSI X3.4, and the Extended Binary Coded Decimal Interchange Code (EBCDIC) are computer character encoding sets. Although there are a number of variants of ASCII, all of them are essentially the same and the ASCII encoding system is often praised by computer scientists for its simplicity and adaptability. EBCDIC is considered an anachronism in the computer world as it was designed for the now superannuated punch cards of the nineteenth century. ASCII, on the other hand, was developed in the nineteen sixties and is very much designed for use in the world of modern computing.

Both ASCII and EBCDIC were based on the Baudot code – a nineteenth century alternative Morse code – but they were designed for different purposes and to different ends. Essentially a seven-bit code, ASCII allows the eighth most significant bit (MSB) for error checking, but most contemporary computer systems use the ASCII codes above 128 for extended character sets. Whereas ASCII is a character encoding set common on a number of different computer systems, EBCDIC is a character set particular to IBM mainframes.

In contrast to ASCII, EBCDIC uses the quota of available eight bits and therefore forgoes parity checking, but EBCDIC has a greater range of control characters than ASCII. However, EBCDIC’s advantages over ASCII are limited to this fuller scope of control characters and EBCDIC’s suitability to its use on punch cards and its inclusion of the American cent character that ASCII omits. However, often EBCDIC where ASCII includes the following characters: []\{}^~¦ and ¢.

Some of the characters missing from the EBCDIC character set and found in the ASCII character set are in the UUencoding range with the consequence that internet attachment mail is often corrupted. Moreover, there are many variants of EBDIC and among these variants there exist types that are incompatible with each other. This problem is exacerbated because documentation of EBCDIC is hard to obtain from IBM, in contrast to ASCII which is well documented and widely available.

There are pieces of software that allow users to convert between the two, but with EBCDIC remaining an IBM proprietary character encoding system and ASCII a much more disseminated system, it appears only a matter of time before ASCII’s status of de facto encoding system becomes the de jure one among computer users.