The LaserWriter 6.z.1 driver is on AppleLink in the Tech Info Library. Use
the search criterion of "LaserWriter 6.z.1".
Also, the LaserWriter 6.1 driver defaults to black and white or Color/Gray
scale, depending on what was used last. The LaserWriter 6.1 driver is on
the Macintosh Printing Tools disk that comes with the Personal LaserWriter
LS and the StyleWriter.