Service manual

Formatter system
The formatter coordinates the major systems. It is responsible for the following tasks:
■ Receiving and processing print data from the printer interface (the computer)
■ Monitoring the control panel and relaying printer-status information
■ Coordinating image formation and timing with the print engine
■ Communicating with the host computer through the bidirectional interface
The formatter receives print data from the parallel interface or the universal serial bus (USB) interface
and converts it into a dot image. The ECU synchronizes the image-formation system with the paper-
feed system and signals the formatter to send the print-image data to the laser system. The formatter
sends the print-image data (dots) in the form of a video signal, and the printing process begins.
Central processing unit
The formatter uses an embedded Coldfire V4 microprocessor operating at 133 MHz.
RAM
■ One bank of nonvolatile RAM (NVRAM) stores parameters.
■ Dynamic random access memory (DRAM) provides temporary storage of the product program code
and print data.
■ The HP LaserJet 1010 and 1012 printers have 8 MB of RAM.
■ The HP LaserJet 1015 printer has 16 MB of RAM.
■ The HP LaserJet 1020 printer has 2 MB of RAM.
USB interface
The formatter receives incoming data through the USB interface. This interface provides high-speed,
two-way communication between the printer and the host, allowing applications on the host computer
to change printer settings and monitor printer status. The USB interface is compatible with the USB 2.0
specification.
Parallel interface (HP LaserJet 1015 printer only)
If the parallel interface on the HP LaserJet 1015 printer is used, the formatter receives incoming data
through bidirectional ECP. Like the USB interface, the parallel interface supports high-speed, two-way
communication between the printer and the host, so applications on the host computer can change
printer settings and monitor printer status. Use an IEEE 1284-compliant parallel cable.
Control panel
The control panel consists of the following components:
■ Three status lights (HP LJ 1010 series printers) or two status lights (HP LJ 1020 printer)
■ G
O and C ANCEL J OB buttons (HP LJ 1010 series printers)
ENWW Formatter system 47