The Macintosh IIci ROMs have been tested only in the Macintosh IIci. They
may work properly in the Macintosh IIcx or Macintosh SE/30, but there
would be no perceptible improvement in performance. Using the Macintosh
IIci ROMs would not cause the Macintosh IIcx or Macintosh SE/30 to support
the "burst mode" abilities of the MC68030 microprocessor. The Macintosh
IIci and the Macintosh IIfx are the only Macintosh computers that have the
hardware to support the "burst mode". We do not support using the
Macintosh IIci ROMs in a Macintosh IIcx or Macintosh SE/30.