All Japanese-enabled versions of HTBasic use the ISO-932 single-byte and Shift-JIS character double-byte sets for character representation when run in Japanese mode. These are the same character sets used by HP BASIC. The ISO-932 character set is the same as the ASCII set for characters whose values are less than 128. Characters whose values are between CHR$(129) and CHR$(159) or between CHR$(224) and CHR$(252) are used as leading bytes for two-byte characters using the Shift-JIS character mapping. Characters whose values are between CHR$(161) and CHR$(223) are half-width katakana characters from the ISO-932 character set. CHR$(160) is a space. CHR$(128) and CHR$(253) - CHR$(255) are undefined.
Non-ASCII characters are entered into HTBasic programs using the operating system’s Input method. ASCII, katakana, and hiragana characters are entered using the normal keyboard keys together with special shift keys. Kanji are usually entered by allowing the user to type a phonetic (ASCII, katakana, or hiragana) representation of the desired character on the keyboard and pressing a convert key, which displays a list of possible characters at the bottom of the screen or in a separate window. The user then chooses the desired character from the list.
