HP 2100 Service Manual - Page 83

Formatter Hardware, Formatter Subsystems, Resolution Enhancement technology (REt - 600 dpi only) - laserjet jetdirect

Page 83 highlights

Formatter Hardware The formatter system contains the following: • CPU. 66 MHz Intel 80960JD with a 33 MHz bus. • Read Only Memory (ROM). Stores the dot patterns of internal character sets (fonts) in addition to storing microprocessor control programs. • Random Access Memory (RAM). Stores printing and font information received from the host system, and can also serve to temporarily store a full page of print image data before the data is sent to the print engine. Note that adding memory will not increase I/O buffer space or cause the printer to print more pages per minute. • Non-Volatile Memory (NVRAM). Stores information about the I/O and print environment configuration. The printer keeps the contents of NVRAM when the power is turned off or disconnected. (As in other HP LaserJet printers, downloaded fonts and macros are saved in conventional RAM and are lost when power is turned off.) • Interfaces • Parallel Interface. Receives incoming ASCII data through its IEEE1284 B interface connector. The IEEE1284 B interface provides high-speed, two-way communication between the printer and the host, letting the user change printer settings and monitor the printer's status from the host computer. • LocalTalk I/O. Implements the AppleTalk networking protocol through the LocalTalk hardware. The LocalTalk network cable (HP P/N 92215N) is connected through an 8pin DIN connector on the printer's I/O panel. • EIO. PCI-based Enhanced Input/Output (EIO) slots support a wide range of print servers, memory, or other add-on devices. HP JetDirect EIO cards provide highspeed communication for network printing over Ethernet, Ethernet and LocalTalk, Token Ring, or Fast Ethernet networks. Formatter Subsystems Resolution Enhancement technology (REt - 600 dpi only) • Contains circuitry for Resolution Enhancement technology (REt), which modifies the standard video dot data on its way to the Engine Controller Assembly to produce smoothed black-to-white boundaries. The default is On. Print Density Adjustment • Affects the line width (boldness) of the print image. This is accomplished by varying the developer DC bias, which controls the amount of toner applied to the photosensitive drum. Settings range from 1 (lightest) to 5 (darkest). The default is 3. C4170-90959 Formatter Subsystems 73

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C4170-90959
Formatter Subsystems
73
Formatter Hardware
The formatter system contains the following:
CPU
. 66 MHz Intel 80960JD with a 33 MHz bus.
Read Only Memory (ROM)
. Stores the dot patterns of internal character sets (fonts) in
addition to storing microprocessor control programs.
Random Access Memory (RAM)
. Stores printing and font information received from
the host system, and can also serve to temporarily store a full page of print image data
before the data is sent to the print engine. Note that adding memory will not increase I/O
buffer space or cause the printer to print more pages per minute.
Non-Volatile Memory (NVRAM)
. Stores information about the I/O and print
environment configuration. The printer keeps the contents of NVRAM when the power is
turned off or disconnected. (As in other HP LaserJet printers, downloaded fonts and
macros are saved in conventional RAM and are lost when power is turned off.)
Interfaces
Parallel Interface
. Receives incoming ASCII data through its IEEE1284 B interface
connector. The IEEE1284 B interface provides high-speed, two-way communication
between the printer and the host, letting the user change printer settings and monitor
the printer’s status from the host computer.
LocalTalk I/O
. Implements the AppleTalk networking protocol through the LocalTalk
hardware. The LocalTalk network cable (HP P/N 92215N) is connected through an 8-
pin DIN connector on the printer's I/O panel.
EIO
. PCI-based Enhanced Input/Output (EIO) slots support a wide range of print
servers, memory, or other add-on devices. HP JetDirect EIO cards provide high-
speed communication for network printing over Ethernet, Ethernet and LocalTalk,
Token Ring, or Fast Ethernet networks.
Formatter Subsystems
Resolution Enhancement technology (REt - 600 dpi
only)
Contains circuitry for Resolution Enhancement technology (REt), which modifies the
standard video dot data on its way to the Engine Controller Assembly to produce
smoothed black-to-white boundaries. The default is On.
Print Density Adjustment
Affects the line width (boldness) of the print image. This is accomplished by varying the
developer DC bias, which controls the amount of toner applied to the photosensitive
drum. Settings range from 1 (lightest) to 5 (darkest). The default is 3.