Lexmark Dot Matrix Technical Reference - Page 123

Count Font ID Byte Start Data Count is the number of bytes of data being downloaded starting with the font ID byte. The count is a 2-byte value downloaded as the low byte followed by the high byte. The font ID byte is a 1-byte number that identifies the font. The ID byte for the 249x is 35 (x23). When downloading character data, the start address is the absolute address of the start of the character data. When downloading lookup table data, the start address is the address of the new entry in the lookup table. The start address is a 2-byte hexadecimal value downloaded as the low byte followed by the high byte. When data is character data, it comes from the character design. When downloading lookup table data, data is as follows: Bit 1, 2, and 3 (Attribute Byte 1) 7 6 5-0 4 (Attribute Byte 2) 7, 6 5-0 Bit Values 1 0 1 The number of character data dot columns stored in memory. 0,0 Shading character. 0,1 Line drawing character. 1,0 Underscore character. 1,1 Not supported. For a 10 cpi Letter Quality 36 column character, bits 5-0 would be 35. Functions The absolute address of the character's image data. Indicates that this is a block graphic character (connects at 6 LPI). Indicates a downloaded character. Indicates a resident character. The type of block graphic character. The type of block graphic character. The type of block graphic character. The type of block graphic character. The number of dot columns of character data printed minus one. 123 Section 7: Downloading Characters and Fonts