When the LaserWriter Pro 810 powers on, it checks to see how much memory is available and automatically allocates the largest page buffer possible at the highest resolution. Thus, for a 16MB configuration, approximately 14.1MB is
used to create a page buffer for a ledger-sized page at 800dpi.
The remaining 1.9MB of memory is used for such things as the PostScript interpreter itself, PostScript dictionaries, display list, font caching, and program memory.