PORTIBM PC Portable (uses same BIOS as XT) 0238-023B - Bus Mouse Port (secondary address)
InstallCheck: read the ID Port twice; if installed, the first byte
	  returned will be DEh, and the second will vary by card
	  (revision number???)
Note:	secondary address for bus mice from MS and Logitech, and the ATI
	  video adapter mouse
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 023Ch"Mouse"

0238  ?W  Command port
0239  ?W  Data port
023A  R?  ID Port