Dynapro Technologies Dynapro ET TCS, Руководство разработчика приложений

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Because the contents of the Standard and Extended Character Sets determine how characters
appear when graphic codes are sent by the host, the TCS allows the contents of these two
character sets to be altered by the host program at will. To facilitate changes to the character sets,
the TCS contains four character fonts which, in conjunction with the character sets, can be used
to dynamically alter the appearance of characters displayed by the TCS.
Although both character sets and character fonts contain similar information (the sixel
representations of characters), the TCS uses only the character sets when a graphic code received
from the host is translated into a character for display. The character fonts merely store
information that can be transferred (mapped) into use by the character sets.
Two of the character fonts are stored in ROM and provide the default contents for the Standard
and Extended Character Sets as shown in Appendix C. The other two character fonts are
changeable (dynamic) and are programmable by the host.
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The Static ASCII and Static Special Character Fonts are stored in ROM and cannot be changed
by the host program. These two character fonts contain sixel information, which defines the
appearance of characters when either of these fonts is mapped into the Standard or Extended
Character Sets using the Map Character Font command.
The Static ASCII Character Font contains standard ASCII characters and special control code
mnemonic characters, which are used within the Communication Monitor.
The Static Special Character Font contains special box drawing characters, international
characters, graphics characters, and special error characters used by various commands within
the TCS.
Unless the host specifies otherwise, the Static ASCII Character Font is mapped into the Standard
Character Set, and the Static Special Character Font is mapped into the Extended Character Set.
The contents of these Static Character Fonts are shown in Appendix C.
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In addition to the two Static Character Fonts already described, the TCS contains two Dynamic
Character Fonts known as Dynamic Character Font 1 and Dynamic Character Font 2.
Each of these dynamic fonts contains sixel information, which defines the appearance of
characters when either of these fonts is mapped into the Standard or Extended Character Sets
using the Map Character Font command.
The contents of each of these fonts can be modified by the host using the Copy Character Font
command and the Down-Line Load Character Font command. Both of these commands are
described later in this chapter.