The basis of many PC code pages is [[ASCII]], originally a 7-bit code representing, at most, 128 characters and control codes. In the past, 8-bit representationsextensions ofto the ASCII typicallycode often either set the top bit to zero, or used it as a [[parity bit]] in network data transmissions. When this bit was instead made available for representing character data, another 128 characters and control codes could be represented. IBM used this extended range to encode characters used by various languages. No formal standard existed for these ‘[[Extended ASCII|extended character sets]]’; IBM merely referred to the variants as code pages, as it had always done for variants of [[EBCDIC]] encodings. [[#/LTH]
