Tech Comm has driven an ImageWriter/ImageWriter II at distances up to 12 feet
without difficulty. The RS-232 standard specifies a maximum of 50 feet using
the maximum voltage (+/-25V).
If one side of the output device is grounded, to convert the signal from RS-422
to RS-423 signalling, the printer should workable at (approximately) a maximum
of 50 feet away.
(NOTE: Since most Macintoshes use the same output device, the 26LS30, this
information is relevant for most systems.)