This encompasses the character sets Printing-ASCII, Japanese-JISX0201-Roman (the left half of JISX0201; this character set is very similar to Printing-ASCII and is a 94-character charset), Japanese-JISX0208, and Japanese-JISX0201-Kana. It uses 7-bit bytes.
Unlike Japanese EUC, this is a modal encoding, which means that there are multiple states that the encoding can be in, which affect how the bytes are to be interpreted. Special sequences of bytes (called escape sequences) are used to change states.
The encoding is as follows:
Character set Representation (PC=position-code)
------------- --------------
Printing-ASCII PC1
Japanese-JISX0201-Roman PC1
Japanese-JISX0201-Kana PC1
Japanese-JISX0208 PC1 PC2
Escape sequence ASCII equivalent Meaning
--------------- ---------------- -------
0x1B 0x28 0x4A ESC ( J invoke Japanese-JISX0201-Roman
0x1B 0x28 0x49 ESC ( I invoke Japanese-JISX0201-Kana
0x1B 0x24 0x42 ESC $ B invoke Japanese-JISX0208
0x1B 0x28 0x42 ESC ( B invoke Printing-ASCII
Initially, Printing-ASCII is invoked.