Compuprint MDP 30FB Programmer's Manual page 73

Byte 1, 2 The absolute address of the character definition.
Byte 3 :
- Bit 7 1: indicates that the character is a graphic character (connects at 6 lpi)
0: indicates that the character is an alphanumerical character
- Bit 6 0: indicates a DLL character
1: indicates a resident character
- Bit 5 to 0 These 6 bits indicate the effective number of dot columns of the character
shape stored in memory.
Byte 4:
- Bit 7, 6 Graphic character description:
- 0: shading character
- 1: line drawing character
- 10: underscored character
- 11: not supported
All graphics characters are 30 dot high. An underscored character is defined
as a blank graphic (all zeros) and it is automatically generated by the printer.
A shading character repeats dots 1-6 of each column as dots 25 through 30
respectively. A line drawing character repeats dots 23 and 24 as the pairs 25
and 26, 27 and 28, 29 and 30.
- Bit 5 to 0 The number of dot columns of the character shape minus one. For example: the
character width of Draft generator is 10 dots and bit 5 to 0 must be set to 9.
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