HP 4 FAMILY - Manual (Page 167)

5
Memory Usage
Introduction
In some situations, the amount of available memory for
printing pages may be smaller than that required for
printing. To make more effective use of the available printer
memory, newer HP PCL 5 printers incorporate new
methods for managing memory. This smaller amount of
available memory is made more usable by:
Memory Enhancement technology, MEt, (available on all
HP LaserJet 6, LaserJet 5, and LaserJet 4 family
printers except the 4, 4M, 4Si and 4SiMx)
Adaptive Data Compression, ADC, (available on HP
LaserJet 4, 4M, 4Si, 4SiMx and DeskJet 1200C printers)
Following recommended practices for transmitting data,
especially raster graphics, to the printer
For the HP LaserJet 4L, using Raster Graphics Adaptive
Compression (PCL compression mode five)
All HP LaserJet 4, 5 and 6 family printers have internal
programming for optimizing the use of limited memory. HP
LaserJet 4, 4M, 4Si, 4SiMx, and DeskJet 1200C printers
compress raster graphics data using a system called
Adaptive Data Compression or ADC. The other HP
LaserJet 4 / 5 / 6 printers use MEt to compress not only
raster graphics data, but also to compress fonts, improve
memory usage for page protection, and provide an overall
improvement in memory efficiency. Both systems operate
automatically and without any intervention from the user.
The HP Color LaserJet printer has memory management
features similar to MEt, but has additional features for
color processing.
Memory Usage 5-1