Unit 1: PCL Emulation
Page 1-34 SATO D512 PCL Programming Manual
DELTA ROW
Delta Row is a compression mode that identifies and transmits only those
bytes different from the ones in a preceding row. The control byte consists of
two parts:
• High 3 bits: Number of bytes to replace +1 (1 to 8).
• Low 5 bits: Offset from last unmodified byte (0-30); if the offset is 31,
the next byte(s) is added to the offset until the next byte is not 255.
Example:
ESC*p300x1200Y |Move cursor to 1" x 4"
ESC*b3M |Set compression to Delta Row
ESC*r1A |Start raster graphics at current
position
|Num Offset
ESC*b9W 'E0FFFFFFFFFFFFFFFF'x |'111 00000'b=8 at 0:
'FFFFFFFFFFFFFFFF'x
ESC*b9W 'E08000000000000001'x |8 at 0: '8000000000000001'x
ESC*b0W |No bytes change
…
ESC*b0W |No bytes change
ESC*b9W 'E0FFFFFFFFFFFFFFFF'x |8 at 0: '8FFFFFFFFFFFFFF'x
ESC*rB |End graphics