HP LaserJet 4000 Printer series - HP DeskJet 1600C Printer

ENWW

Printer-Specific Differences 2-91

Additional features include:

• Simplified Control Panel. The IEEE-P1284 ECP port

described below allows front-panel simplification and the
elimination of DIP switches. The DeskJet 1600C control panel
is similar to that of the LaserJet 4L, with one button and four
LED indicators.

• IEEE-P1284. This bi-directional enhanced capability port

(ECP) allows most printer features to be monitored and
controlled through Microsoft Windows or a DOS remote control
panel shipped with the product. In previous HP printers, PJL
provided some job-level status and control, but PJL is
embedded in the data stream, synchronous with the printer
description data. With the implementation if MLC (Multiple
Logical Channels) on the ECP and MIO 6.0, the printer can be
controlled and monitored on a separate channel,
asynchronous to the data stream. PJL still provides control
that must be synchronous with the data stream.

• E

NERGY

S

TAR

. The printer lowers its power consumption if it

has not been used for 15 minutes.

• Out-of-Ink Sensing. An LED on the control panel lights when

a pen runs out of ink.

• MIO. Modular I/O interface with auto-sensing I/O configuration.

• JetDirect. Optional network cards: Novell, TCP-IP, LocalTalk,

EtherTalk, and third party.

• PostScript. A SIMM upgrade is available.

• Optional Media Source. An optional sheet feeder tray is

available.

• Media Detection. Automatic detection of media size and

media type (transparency).

2-92 Printer-Specific Differences

ENWW

• PJL. Unlike the DeskJet 1200C, which implemented only the

PJL kernel, the DeskJet 1600C printer supports all of the PJL
commands listed below. Full PJL implementation is not
needed because of the multiple-channel capability of the
IEEE-P1284 Extended Capabilities Port. DeskJet 1600C also
supports page protection with the @PJL SET PAGEPROTECT
command.

• Print Modes. The DeskJet 1600C has the following

user-selectable print modes:

EconoFast. The primary goal is cost per copy. The secondary
goal is high speed.

Presentation Graphics. Best quality graphics.

Normal. Equal emphasis on quality and throughput. Best
mode for most uses, minimizing the need to switch to other
modes.

COMMENT

INQUIRE

DEFAULT

JOB

ECHO

RESET

ENTER

SET

EOJ

UEL

ENWW

Printer-Specific Differences 2-93

Media Source Command

The Paper (Media) Source command (

?

&l#H) for the DeskJet 1600C

uses a value of 5 for its optional sheet feeder and also supports a
value of 7 (autoselect). A value of 7 selects the current printer default
source. The user, through the application, may select a particular tray
for the first page or pages (for example, a fancy cover page), then
choose autoselect to pull paper from a default tray (for example,
containing standard paper). This is different than option 0, which
continues printing from the currently selected source. The “default”
source may be user-selected, or based upon the printer's own
algorithm.

Compression Method Command

The Compression Method command (

?

*b#M) for the DeskJet 1600C

supports Method 9 compression (compressed replacement delta row
encoding) in addition to compression methods 0, 1, 2, 3, and 5.

Method 9 (Replacement Delta Row Encoding)

Like Method 3, this method replaces only bytes in the current row that
differ from the preceding (seed) row. Unlike Method 3, the
replacement (delta) bytes may be encoded.

The replacement byte string (delta compression string) consists of a
command byte, optional offset bytes, optional replacement count
bytes, and the replacement data.

Command

Byte

Optional Offset Bytes

Optional Replacement

Count Bytes

Data Bytes

2-94 Printer-Specific Differences

ENWW

The command byte itself has three parts:

• Control Bit. Determines whether the replacement data is

compressed, and also the bit boundaries of the command
byte's other two fields.

• Offset Count. The left offset (number of bytes) the

replacement data is offset from the current byte position in the
seed row.

• Replacement Count. The number of consecutive bytes to be

replaced. One more byte than the replacement count is
replaced (for example, 6 bytes are replaced by a replacement
count of 5).

Like compression method 3, the “current” byte follows the last
replacement byte; at the beginning of a row, the current byte
immediately follows left raster margin. An offset of 0 indicates the
current byte; an offset of 1 indicates the byte following the current
byte.

The size of the offset count and replacement count fields depends on
the value of the control bit.

CONTROL BIT = 0

If the control bit is 0, the replacement data is uncompressed. If the
control bit is 0, bits 0-2 indicate the replacement count and bits 3-6
indicate the offset count.

If the offset count is 15, an additional offset count byte follows and is
added to the total offset count. If the offset count byte is 255, another
offset count byte follows. The last offset count byte is indicated by a
value less than 255.

If the replacement count is 7, an additional replacement count byte
follows and is added to the total replacement count. If the
replacement count byte is 255, another replacement count byte
follows. The last replacement count byte is indicated by a value less
than 255. One more than the total replacement byte count will be
replaced.

Control Bit

Offset Count

Replacement Count

7

6

3 2

0

Control Bit = 0

Offset Count

Replacement Count

ENWW

Printer-Specific Differences 2-95

CONTROL BIT = 1

If the control bit is 1, the replacement data is run length encoded. the
bit boundaries are different than if the control bit is 0: bits 5-6 contain
the offset count, and bits 0-4 contain the replacement count. As when
the control bit is 0, optional offset bytes and replacement bytes may
be added.

7

6

5 4

0

Control Bit = 1

Offset Count

Replacement Count