Epson DFX-8000 User Manual page 163

The following character definition program should help make this
clear:
The two at signs (Q) in line 120 (no and ti) represent the range of
characters being defined (in this case, a range of one). Line 130
contains al.
The information about the actual character design (which is contained
in the data statements at the end of the program) is sent to the
printer in the loop between hnes 140 and 160.
The example program uses 136 for al (in line 130 of the definition
program), but you can use other values. The number al specifies
two things: the width of the character and its position on the grid.
The width is used when the character is printed in proportional
mode.
If you want to use the bottom eight pins, use the third grid in the
illustration on page 4-23.
A:
User-defined Characters
Software and Graphics 4-25