Apple LaserWriter 12/640 PS - Manual (Page 182)

When the LaserWriter 12/640 PS runs out of paper in one tray, it can
automatically switch and use paper in another paper cassette or the
multipurpose tray. By using automatic tray switching between the 250-sheet
paper cassette and the 80-sheet multipurpose tray, you can print 330 sheets
without reloading paper. If you have the optional 500-sheet cassette and
feeder, and it contains the same size paper, automatic tray switching includes
it as a paper source. Combining all three paper sources lets you print up to
830 sheets without reloading paper.
m
Available printer memory Lets you specify the amount of available printer
memory.
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PhotoGrade Turns PhotoGrade on or off. To use PhotoGrade, your printer
must be upgraded to have at least 12 MB of RAM. PhotoGrade enhances
the printed look of images, such as scanned or digital photographs, to
produce added clarity, finer shading, and better contrast. For documents
that require images to be printed with the best quality that the printer can
produce, turn PhotoGrade on.
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