Lexmark 249X 用户手册

下载
页码 227
Section 7: Downloading Characters and Fonts
120 
249x Printers
Designing and Downloading Characters
The text that follows shows you how to design and download characters for the 
249x printers. The definitions use binary and hexadecimal notation. The 
examples are in the program format shown on page 16. 
Note:
Download fonts must be reloaded after a power off/on cycle.
Downloading a New Font
The first step in downloading a new font is designing and creating the character 
data for the characters in the font. You can download up to 256 characters. You 
may share resident characters by loading the lookup table entry with the 
address of the resident character and setting bit 6 in attribute byte 1 to 1. This 
code indicates a resident character. Set the other bytes of the lookup table entry 
appropriately. After selecting the characters you want to download and those 
you want to use from the resident fonts, you must create the character data and 
download it. Next, you must download the lookup table, being careful to use 
the correct addresses and masks for any shared characters.
The first downloadable address is x800C. This address is the first (high) byte of 
a 2-byte code page ID. The second (low) byte is stored at x800D. A zero code 
page ID lets you switch between the resident fonts and downloaded fonts with 
the ESC I command, Select Print Mode. If the code page ID of the download 
font is not zero and does not match the selected resident font, then a Set Code 
Page
 command is required to select the font.
Note:
The ESC = 00 command copies the current code page to the code page ID.
Address x800E and x800F are reserved and you should set them to zero.
The first lookup table must always begin at address x8010. If a second lookup 
table is present, it must begin at x8911. A third and fourth lookup table should 
begin at x9212 and x8B13, respectively. Four is the maximum number of lookup 
tables that may be accessed. Character data can begin at address xA414 or 
greater.
The first byte of any lookup table is the font descriptor byte. This byte should 
not be changed unless you are downloading a new lookup table. Changing this 
byte does not change the font characteristics. If the font descriptor byte does not 
match the characteristics of the font you have downloaded, the characters are 
unrecognizable when printed.
The font descriptor byte identifies the default font. (The first font marked 
default is chosen if no user-defined default has been stored using the operator 
panel menu.) This byte also tells if another lookup table follows this one and 
identifies the quality of the font. If the default font has a non-zero code page ID, 
that code page ID becomes the active code page when the printer is switched