Lexmark 248X ユーザーズマニュアル

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Section 7: Downloading Characters and Fonts
124 
The Lookup Table
• 
ASCII character 255, xFF, cannot be defined. It is a mandatory space and is 
the same size as ASCII character 32, x20.
• 
ASCII Character 0, x00, is the zero slash. Any character downloaded to 0, 
x00 replaces the zero. If the zero slash is selected from the operator panel, 
the download character is printed instead of ASCII character 48, x30.
• 
All block graphic characters are 30 dots high, even though only 24 dots are 
defined for each column.
An underscore character is defined as a blank-block graphic character (all 
zeros). The underscore is generated by the printer during the second pass.
A shading-block graphic character repeats dots 1-6 of each column as dots 
25 through 30, respectively.
A line-drawing-block graphic character repeats dots 23 and 24 as the pairs 
25/26, 27/28, and 29/30.
• 
An entry can point to any character data image whether resident or down-
loaded. Multiple entries can point to the same image. The address of an 
undefined entry should be zero. An undefined entry is printed as a space.
Managing the Download Area
If you are downloading and know the status of preceding downloaded 
information, you should not have any conflicts in character management. If, 
however, there is previously downloaded information in the download area 
and you are not sure of its status, you can write over the download area with 
the resident lookup tables for the currently selected code page. To write over 
any existing download data, send the printer command ESC = 0 0. Sending 
ESC = 0 0 
clears the existing download data and copies the resident lookup 
tables to the download area.
5-9
Used for the compression mask. There is 
one bit per dot column with bit 7 of byte 5 
mapping to the leftmost column. For a 
character with 36 dot columns when 
decompressed, bit 4 of byte 9 would map to 
the rightmost column.
All zeros indicate that a character is not 
compressed.
If a proportional character has more dot 
columns than compression mask bits, the 
remaining dot columns must be stored 
without compression.
Only 39 dot columns can be compressed. 
Bit 40 of the compression mask is reserved.
Bit
Bit Values
Functions