Microcom 438 - Manual (Page 113)

Downloadable Fonts Chapter 7
7-4 438 Operator’s Manual - 880052-0100
8-bit data connections. This command is usable on data connections that support either 7
or 8-bit data.
The following is the format of the ^D104 command when used for a GRAPHIC image file:
^A<Slot Number>^D104
<Rotation> <Count> <Image Data>
Where:
<RAM Memory Slot Number> is the memory slot location (1-255) where the GRAPHIC will
be saved in the printer’s volatile RAM memory. The printer uses the same TCI of “8” to
select downloadable fonts or graphics. Therefore a font and a graphic cannot have the
same Slot Number or CGN number.
<Rotation> is an 8-bit integer, 0 for an upright font and 1 for a 90-degree rotated image.
<Count> is a 32-bit integer, least significant byte first. This is the number of bytes that the
image uses.
<Image Data> is the graphic image data that has been converted to ASCII-HEX.
ASCII-HEX Conversion
The ASCII-HEX conversion is performed by ORing the most significant and least significant
nibbles of every byte with “30” HEX.
For Example: To convert the byte “6C” to ASCII-HEX, simply OR the first and second
nibbles with “30” HEX. This results in the two bytes “36” HEX and “3C” HEX. This
conversion results in a file size that is twice as big as the source but the data can now be
transmitted over a 7-bit data connection.
7.4.3 Save FONTS to FLASH (^D135)
^A ^D
COMMAND
xxyy 135 Save FONTS to FLASH.
This command is not normally seen by the user. It is put into a FONT file by
the FONT converter program which generates a special ^Axxyy^D135 code
which is placed at the beginning of the FONT download file. The ^Axxyy tells
the printer the overall size of the file according to this format:
xx = the number of additional 64KB sectors in the FONT file set
yy = CGN # (1-255)
If xx = 00, then the FONT fits into one 64Kbyte sector of memory and there
are no additional sectors required for the FONT.
If xx > 00, then the FONT is larger than one 64KB sector, and xx is the
number of ADDITIONAL 64KB sectors needed for the FONT. The xx field >
00 signals the printer to get ready for a multi-sector FONT download. Each
subsequent download contains a header with the xx field decremented by 1.
The last download file has a header field xx = 00.