HPlogo MPE XL Native Language Programmer's Guide: 900 Series HP 3000 Computer Systems

Appendix D Converting 7-Bit to 8-Bit Data

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Many Hewlett-Packard peripherals can be configured for 7-bit operation with one of the European language national substitution character sets. These peripherals must be converted to 8-bit operation to access Native Language Support (NLS) capability. NLS requires the use of 8-bit character sets that include USASCII and native language characters.

NLS for western European languages is based on the ROMAN8 character set in which the additional characters required are assigned to unique values between 128 and 255. Eight bits are required to hold the value of a ROMAN8 character. All the special European characters are accessible in ROMAN8 without losing any of the USASCII characters.

The 7-bit national substitution sets do not offer a full complement of characters. New characters replace existing ones. For example, in FRANCAIS, the graphic symbol # is not available. In Spanish and French, even the substitutions made are not sufficient to obtain all the necessary new characters. The use of mute characters is required. Mute characters provide a single graphic on the terminal screen or paper for two bytes of storage and two keystrokes. For example, an e in Spanish or French would be produced with an accent mark plus an e, whereas ROMAN8 contains the e as a single character. In any one language, the graphic symbols for other European countries are not available at all. For example, a French user does not have access to the necessary characters to properly address a letter to someone in Germany. The ROMAN8 8-bit character set eliminates these problems.

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