LaserWriter as a Serial Printer



I've been doing some work with the Asynch LaserWriter drivers,
testing a mixed DOS/Macintosh environment.

1) When the LaserWriter is used as a serial printer, does it respond to ASCII
codes with the 8th bit set the same as codes with the 8th bit not set? For
example: Is 83h = 03h, 84h = 04h, 93h = 13h, 91h = 11h?

2) Does the LaserWriter respond to the above control codes when in AppleTalk
mode as well as when in serial mode?

These questions are interrelated, and the answers may be easier to follow if we
answer #2 first.

2) A control code is used by a printer for a specific printer function. When
the printer is in AppleTalk mode, the PostScript program language is used,
and uses words to activate or invoke printer functions, not control codes.
However, the printer uses control codes if it is in Diablo or LaserJet (if
available) emulation mode.

1) If the printer is in Diablo or LaserJet mode, the above is correct if it is
set for 7-bit data with no parity check, as the 8th bit is dropped -- but if
the printer is in 8-bit mode, the mapping is not equivalent.

(NOTE: Part of the printer configuration requires you to select whether 7- or
8-bit communication and parity is used, so
Published Date: Feb 18, 2012