Brother Laser Printer HL1660e User Manual
Page 103
2001/10/02
CHAPTER 2 "PCL" - 83
<Second section 66 66 66 66>
Offset count = 2
Replacement count = 4
Replacement data = 66
1
1
1
0
0
0
0
1
7
6
5
4
3
2
1
0
Replacement count = 1 + 2 = 3
Offset count = 3
Optional offset count byte = 0
Replacement data = 11
1
1
0
0
0
1
0
7
6
5
4
3
2
1
0
Replacement count = 2 + 2 = 4
Offset count = 2
Replacement data = 66
0
•
# = 1152 indicates that CCITT G3/G4 data compression is to be used.
This format is popular in optical document storage areas as this compression is effective to store black and
white type pictures. As G3/G4 format does not have picture size/resolution information, the printer requires a
header at the beginning of t he picture data. The header size is 94 Bytes. Both the header and the picture data
are transferred by the ESC*b###W(###=data length) command. The normal PCL transfer graphics data
command has a limitation on the data size and ### should not exceed 32767. Unlike other modes, this mode is
special and does not have the 32767 size limitation. The data must have the following structure - Header and
Picture data. The values in this mode are little endians.
Byte
position
Data
Description
0 - 1
6E 6E
'nn' This is header ID.
2 - 3
0A 00
Reserved
4 - 7
5E 00 00 00
Picture data start offset from header top
8 - 11
File length
File length including 94 Byte header. If file length is 65,536 byte,
these 4 bytes become "00 00 01 00"
12 - 13
01 00
Reserved
14 - 15
01 00
Reserved
16 - 19
4A 00 00 00
Reserved
20 - 21
Compression mode
02 00: Fax MH format
03 00: Fax MR format
04 00: Fax G4 format
22 - 55
00 ... 00
All zero
56 - 59
Picture data length
If picture data length is 65,442 (65,536 ~-94) byte, these 4 bytes
become "A2 FF 00 00."
60 - 61
01 00
bit / pixel
62 - 63
01 00
bit / pixel
64 - 65
Pixels/line
If picture dot width = 2,400, these 2 bytes become "60 09"
66 - 67
Pixels/line
Same as above.
68- 69
Lines/picture
If picture dot count = 3,100, these 2 bytes become "1C 0C."
Header
Picture data
94 bytes
Picture
data
length
File Length