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EasyCoder E4 Direct Protocol v2.10 – Programmer’s Reference Manual
73
Chapter 9
Advanced Features
The data input to text fi elds and bar codes takes the form of an
ASCII string. Even compound data, such as...
PRTXT "Label No.";CNT1$;" Date ";DATE$("F")
is expanded by the printer into a single ASCII string before any
other processing occurs. This ASCII string is then converted to a
string of international character codes according to the Unicode
standard. Every character, whether it be a Latin “A”, Greek
“alpha” or Chinese “ren”, has a unique code in this standard,
called its “unicode”.
Unicoded fonts
The EasyCoder E4 works with Unicoded fonts in either Bit-
stream Speedo or TrueType format: its font scaler accesses images
of characters within these fonts according to the character’s uni-
code. The printer also supports a number of non-Unicoded fonts.
Some care is required when using fonts not built into the printer:
• If a font is not Unicoded, the font scaler may access the wrong
characters (only some non-Unicoded fonts are supported).
• A font may not include all the characters in the current
character set, as specifi ed by the
NASC
command. If a text
fi eld contains a character which is not in the current font, then
a replacement character will usually be printed instead. The
replacement character for Speedo fonts is a space, while for
TrueType fonts it is usually an unfi lled rectangle.
NASC and NASCD tables
There are many national and international standards for mapping
ASCII strings to strings of unicode. The EasyCoder E4 provides
support for virtually all of these. There are two types of mappings:
• Single-byte mappings, which map one ASCII character to
a unicode. The EasyCoder E4 supports these using “NASC
tables”. For example, for each NASC setting listed in Chapter
6.11, the EasyCoder E4 has an internally stored NASC table.
User defi ned NASC tables can also be stored in the printer as a
fi le (see later in this chapter).
• Double-byte mappings, which map pairs of ASCII characters
to unicodes. The EasyCoder E4 supports these using
“NASCD tables”. Currently, there are NASCD tables for the
most common double-byte mappings used for the large Asian
character sets: BIG5, GB, JIS and Shift-JIS.
2. Using International Character Sets