ASMO 449


ASMO 449 is a 7-bit coded character set to encode the Arabic language.

History

This character set was devised by the now extinct Arab Standardization and Metrology Organization in 1982 to be the 7-bit standard to be used in Arabic-speaking countries. The design of this character set is derived from the 7-bit ISO 646 but with modifications suited for the Arabic language. In code points ranging from 0x41 to 0x72, Latin letters were replaced with Arabic letters. Punctuation marks which were identical the in Latin and Arabic scripts remained the same, but where they differed, the Latin ones were replaced by Arabic ones. Only nominal letters are encoded, no preshaped forms of the letters, so shaping processing is required for display. This character set is not bidirectional and was intended to be used in right to left writing. Therefore, symmetrical punctuation marks appears as reversed ", ".
ASMO 449 was registered in the International Register of Coded Character Sets as IR 089 in 1985 and approved as an ISO standard as ISO 9036 in 1987.

Character set

There is a variant, sometimes named ASMO 449+ which adds the characters NBSP in 0x75, "ﹳ" in 0x76, "لآ" in 0x77, "لأ" in 0x78, "لإ" in 0x79 and "لا" in 0x7A.

Relationship with other character sets

ASMO 449 is a 7-bit character set. Although some encodings allocate this 7-bit character set in the upper part of the 8-bit character set, it should not be confused with ASMO 708. In the character sets that allocate ASMO 449 in the upper part of the 8-bit character set, the existence of apparently repeated characters is due to the fact that the characters in the lower part are for left-to-right script while the characters in the upper part are for right-to-left script. When ASMO 449 is allocated to the upper part of the 8-bit character set, it has Arabic digits.