The earlier seven-
bit U.S.
American Standard Code for Information Interchange ('ASCII') encoding has characters sufficient to properly represent only a few languages such as English, Latin, Malay and Swahili. It is missing some letters and letter-diacritic combinations used in other Latin-alphabet languages. However, since there was no other choice on most US-supplied computer platforms, use of ASCII was unavoidable except where there was a strong national computing industry. There was the
ISO 646 group of encodings which replaced some of the symbols in ASCII with local characters, but space was very limited, and some of the symbols replaced were quite common in things like programming languages. Most computers internally used eight-bit bytes but communication (seen as inherently unreliable) used seven data bits plus one
parity bit. In time, it became common to use all eight bits for data, creating space for another 128 characters. In the early days most of these were system specific, but gradually the
ISO/IEC 8859 standards emerged to provide some cross-platform similarity to enable information interchange. Towards the end of the 20th century, as storage and memory costs fell, the issues associated with multiple meanings of a given eight-bit code (there are seven ISO-Latin code sets alone) have ceased to be justified. All major operating systems have moved to
Unicode as their main internal representation. However, as Windows did not support the
UTF-8 method of encoding Unicode (preferring
UTF-16), many applications continued to be restricted to these legacy character sets.
The euro sign The
introduction of the euro and its associated
euro sign () introduced significant pressure on computer systems developers to support this new symbol, and most 8-bit character sets had to be adapted in some way. • Apple with MacRoman and
Sun Microsystems with
Solaris OS simply replaced the
generic currency sign (). This caused difficulty in some places because organisations had found other uses for its
code point, such as the company logo. • ISO introduced a further variant of ISO 8859,
ISO 8859-15, which replaced the generic currency sign with the euro sign as well as making some other replacements of symbols with letters with diacritics. ISO 8859-15 never received widespread adoption. • With
Windows-1252, Microsoft placed the euro sign in a gap (position 80hex) in the existing
C1 control codes, a decision that other vendors considered counter-architectural. Whilst these decisions had limited effect for documents that were only used within a single computer (or at least within a single vendor's "
digital ecosystem"), it meant that documents containing a euro sign would fail to render as expected when interchanged between ecosystems. All of these issues have been resolved as operating systems have been upgraded to support
Unicode as standard, which encodes the euro sign at U+20AC (decimal 8364). == Comparison table ==