With the Macintosh Plus, use the Macintosh Peripheral Cable, M-0185, and
connect the 9-Pin end of the M-0185 to the LaserWriter and the Mini-8 end to
the Macintosh Plus printer port.
To connect a single Macintosh or Macintosh XL to a LaserWriter without using
the AppleTalk connector modules, construct a new cable using the following
pinouts:
Macintosh Plus Macintosh Macintosh XL Signal LaserWriter Signal
Mini-Circular 8 DB-9 DB-25 DB-9
4 3 1 GND 3 GND
6 4 20 TXD+ 8 RXD+
3 5 2 TXD- 9 RXD-
8 8 9 RXD+ 4 TXD+
5 9 3 RXD- 5 TXD-
Set the LaserWriter's mode switch for "AppleTalk", use the control panel to
"Connect" AppleTalk, and use "Chooser" to select the LaserWriter.
CAUTION! To avoid FCC Class B signal violation, this cable should be fully
shielded, as the data is at a very high rate and is not attenuated by the
connection boxes normally used in AppleTalk.