Lps System Disk Storage And Memory - Xerox 4890 Product Reference

PRINTER HARDWARE COMPONENTS

LPS system disk storage and memory

Graphic memory
Character dispatcher/image generator
2-2
The 4890 controller houses the 400 MB hard disk, a 5.25-inch
diskette drive, an optional 1/4-inch cartridge tape drive, bays for
three additional hard disk drives of 400 MB each, and a Small
Computer System Interface (SCSI) connection for the peripheral
cabinet high performance tape drives (9-track open reel and 1/2-
inch cartridge).
The system disk stores the operating system software (OSS) as
well as the system resources (fonts, forms, logos, and graphics)
that are loaded into memory for use during print processing.
Figure 2-2.
System memory, residing in the controller, is divided into the
following categories:
Font memory Each character in a font is composed of a unique pattern of dots.
Font memory stores the data representation of each character. If
multiple fonts are needed for a job, more font memory is
needed to meet system demands.
Like font memory, graphic memory stores the data representation
of graphic art to be printed.
The CD/IG memory is specialized memory used to construct a
page before it is sent to the printer for imaging. The form and
text data are merged into a data representation of a printed
page.
Task memory Programs related to the performance of printing tasks (input,
output, forms compiler, PDL compiler, Interpress decomposer,...)
are stored in task memory.
Cache memory This high-speed memory improves processor access to task
memory.
4890 controller
XEROX 4890 HIGHLIGHT COLOR LPS PRODUCT REFERENCE