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<TITLE>The Linux keyboard and console HOWTO: Console generalities</TITLE>
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console!theory of operation
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-->
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Conversely, when you output something to the console, it first undergoes
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the standard tty processing, and then is fed to the console driver.
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The console driver emulates a VT100, and parses the input in order to
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recognize VT100 escape sequences (for cursor movement, clear screen, etc.).
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The characters that are not part of an escape sequence are first converted
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into Unicode, using one of four mapping tables if the console was not
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in UTF-8 mode to start with, then looked up in the table describing
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the correspondence between Unicode values and font positions,
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and the obtained 8- or 9-bit font indices are then written to video memory,
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where they cause the display of character shapes found in the video card's
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character ROM.
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One can load one's own fonts into character ROM using setfont.
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The obsolete programs loadunimap and mapscrn can be used
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to manipulate the Unicode map belonging to the font, or the mapping
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table of the console. More details will be given below.
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There are many consoles (called Virtual Consoles or
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Virtual Terminals, abbreviated VCs or VTs) that share the same
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screen. You can use them as independent devices, either to run
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indendent login sessions, or just to send some output to, perhaps
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from top, or the tail of the system log or so.
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See below (`Console switching') on how to set them up and
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switch between them.
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