Default values are set for the font cache in the LaserWriter IINT and
LaserWriter IINTX, as well as for the display list and communications
buffer. Font cache and display list sizes are persistent parameters and
can be reset.
The default values are (in hex):
2MB or less 3MB or less 3MB or more
Font Cache size $286000 $330000 10% RAM size
Display List size $10000 $150000 10% RAM size
These parameters permit setting the RAM allocation in the LaserWriter
IINTX.
(IMPORTANT NOTE: If the RAM allocations are set incorrectly, it could have
a VERY BAD effect on the operation of the printer. Do not adjust these
unless you know what you are doing, or have consulted with someone who
does!)
Normally, these values are set to 0 in the EEROM (ZPRAM), which tells the
printer to calculate the necessary sizes based on RAM size.
Also, a change has been made to the operation of the font cache in more
recent LaserWriters. Formerly, there was a single limit on the number of
bytes occupied by a character in the cache; a character larger than the
limit would not be cached. Now there are two cache thresholds, an upper
one and a lower one.
If a character is larger than the upper threshold (as determined by the
bounding box specified to setcachedevice), the character is still not
cached; if smaller, it is.
Once the character is cached, if it's larger than the lower threshold it
is compressed; if not, it is stored as a full-pixel array.