APPENDIX H - CONTINUED
ESC & User defined characters
This command is used to define downloadable charactets in-a 9x11 dot matrix.
With this command, the programmer can define a single character or an entire
font.
The variables “cl” and “c2” specify the character range to be defined. For
example, to download four characters into the locations occupied by the letters
“a”, “b”, “c” and “d”, “cl” would equal 97 and “c2” would equal 100. Values for
“cl” and “c2” can range from 0 to 255.
The dot pattern for each character must be defined in terms of an 8 x 11 dot
matrix. That is, each character can be a maximiun of 8 dots tall (See Figure H. 1).
Twelve bytes are used to define a character. The first byte, the attribute byte,
specifies height and width characteristics of the character. The variable “a” is
used to specify the attribute byte. The printer ignores all but the MSB of the
attribute byte. The MSB provides descender data. If the MSB is 0, the
user-defined character occupies the bottom eight dot positions of the matrix as
shown in Figure H.3.
Figure H.3 Epson FX MSB Equal to 0
H-18
