The issue is not the version of the ROM but the version of PostScript
residing in the ROMs. The original LaserWriters started with ROM version 1
or PostScript version 23. The second ROM set for the original LaserWriters
is known as ROM version 2 or PostScript version 38. The third ROM set is
known ROM version 3 or PostScript version 47.
The LaserWriter IINT and LaserWriter IINTX both use PostScript version 47.
However, the ROMs in the LaserWriter IINT and LaserWriter IINTX have additions
to the ROMs, which are in the original LaserWriters. The ROMs in the
LaserWriter IINT and LaserWriter IINTX are considered ROM version 1.0 for
the LaserWriter IINT and LaserWriter IINTX, although the PostScript version
is 47.
Microsoft Windows requires PostScript version 38. In the older
LaserWriters, version 38 of PostScript was also known as version 2 of the
ROM.
The latest versions of Windows (Windows 2.11) and its PostScript driver
(PostScript driver 3.1) do not suffer from this problem and will print to a
LaserWriter II successfully.