HP LaserJet 6L User Manual download pdf (Page 59)

Formatter System

The Formatter PCA is responsible for the following:

• Receiving and processing print data from the printer interface.

• Monitoring Front Panel Button and relaying printer status information.

• Developing and coordinating data placement and timing with the print engine.

• Storing font information.

• Communicating with the host computer through the Bi-Directional Interface.

The Formatter PCA receives print data from the Bi-Tronics Interface and converts it

into a dot image. The DC Controller synchronizes the Image Formation System

with the Paper Feed System and signals the Formatter to send the print image data.

The Formatter sends the print image data (dots) in the form of a VIDEO signal and

the printing process begins.

The Formatter PCA also provides mounting locations for additional memory.

CPU

The Formatter PCA incorporates a Motorola 68030 custom-built microprocessor

operating at 24 MHz.

Read Only Memory (ROM)

Besides storing microprocessor control programs, the ROM stores dot patterns of

internal character sets (fonts).

Random Access Memory (RAM)

The RAM stores printing and downloaded font information received from the host

system and temporarily stores a full page of print image data before the data is sent

to the print engine. (See “Page Protect” later in this chapter.) Memory capacity can

be increased by adding a DRAM memory card to the Formatter PCA. Note that

adding memory may also increase print speed when printing complex graphics.

Parallel Interface

The Formatter PCA receives incoming data through its Bi-Tronics interface. The

Bi-Tronics I/O provides high speed and two-way communication between the

printer and the host, allowing the user to change printer settings and monitor printer

status from the host computer. This interface is IEEE-1284 compliant.

5 - 8 Functional Overview

1 2 ... 54 55 56 57 58 59 60 61 62 63 64 ... 203 204

No comments

HP LaserJet 6L User Manual Page 59