In Diablo 630 Emulation mode, the LaserWriter prints a page under two
conditions: (1) when it reaches the end of a page, or (2) when it receives a
form feed. The LaserWriter cannot detect the end of a document; it simply
assumes that the document has come to an end when data stops arriving.
If the last page of a document isn't full and doesn't end with a form feed, the
printer doesn't print it immediately; instead, it waits for a printer timeout,
which occurs (1) as soon as the next document arrives, or (2) after 30 seconds,
if no document arrives before that. You can avoid this delay by being careful
to include a form feed at the end of your document's last page.
During printing there is a step called data preparation. In this step, the
Laserwriter determines how many pages it takes to print the document. There is
a possibility that one character, even a carriage return, will force the
generation of a blank page at the end of the document. With MacWrite
documents, the Laserwriter prints this last page first.