I work for a company that was unfortunate enough to have bought many 55sx CPUs.
The 55sx is a 386sx/16 computer with fairly lack-luster video performance,
minimal memory upgrade potential, and frankly, NO FUTURE.
For the same $1k you would sink into CD-ROM on that unit, you could almost buy
an entire computer (much faster, better etc.) WITH CD-ROM and Multimedia
support via SoundBlaster or Pro Audio Spectrum. BTW, Creative Labs does make a
Sound Blaster Pro for Microchannel, but it doesn't have the CD-ROM interface
that the ISA model has, AND it costs $400! Wow, microchannel turned out to be
quite a lemon.
Since this sparkling piece of technology only has 3 slots, you couldn't have
much invested in cards, so don't throw any more money away. Believe me, I work
with both MCA and ISA hardware all day long. MCA has NO BENEFIT AT ALL!