Microcom 412 Operator's Manual page 66

Downloadable Graphic Images
Label start:
Word, Word, lookup_table_offset
Word tallest_char
Word widest_char
Byte default_spacing
Byte byte_width
Byte first_char
Byte last_char
Byte default_char
Label lookup_table
Word char_offset[last_char-first_char]
Label first_char_data
Word char_height
Word char_width
Byte bitmap_data[char_height][byte_width] ;bitmap of char, 2d array
The above method allows graphic images to span 64KB memory segments. When using
graphics over 64KB, the printer will determine the number of 64KB slots required to store the
entire graphic, and will split the large file into the correct number of smaller files internally. It will
store these smaller files sequentially in the slots following the one specified in the command.
Therefore, before sending a graphic file that is 64K or more bytes long (uncompressed size),
make sure that the specified font slot and enough following slots to store the file are
unoccupied.
Graphics that are stored in multiple slots in this way may still be printed as if they are one large
graphic. In the label format, refer to the first slot (the one specified in the download command).
The printer will automatically append the additional graphic files seamlessly without additional
user intervention.
58
;the beginning of the file
;distance in bytes from start to beginning
;of lookup_table (4 bytes)
;height of graphic image in dots
;width of graphic image in dots
;default spacing, usually 0
;width of graphic image in bytes
;(20h)
;(20h)
;(20h)
;beginning of lookup table
;array of offsets, one for each character in font.
;Each offset is the distance, in bytes, from start to
;the beginning of the corresponding character's
;data structure. The first word in this array is the
;offset to the first character's data, the last word is
;the offset to the last character's data.
;the beginning of the graphic image data
;height of this char's bitmap in dots
;width of graphic image in dots
;The most significant bit of the first byte in each
;row prints as the right most dot of the character,
;and the first row is the bottom row when printed.
Chapter 6
412 Operators Manual