Date: 20 Apr 1996 00:00:01 EST

  Indigos need special Indigo mice. Replacement mechanical or optical
  (take note, mechanical mice haters!) mice are available from SGI or
  directly from Mouse Systems (510-656-1117).

  Indigo2s and Indys can use PS/2 mice as per the pcmouse(7) manpage.
  Dave Yost expands on this: The Indigo2 takes any industry standard
  mouse of the variety variously known as "IBM PS/2", "Mouse Port" or
  "6-pin". A PC serial mouse won't do, even with an adaptor, unless it
  is claimed to work on a PS/2 through an adaptor. The Logitech
  "MouseMan Cordless" mouse works for me.

  Onyxes use a custom serial mouse. If you'd prefer an optical mouse
  over the standard mechanical mouse shipped with the system, call Mouse
  Systems (510-656-1117) or Qualix (415-572-0200). If you'd like a
  trackball, call Mouse-Trak (800-533-4822, email yvonne@mousetrak.com).