PORTIBM PC Portable (uses same BIOS as XT) 023C-023F - Bus Mouse Port (primary 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:	primary address for bus mice from MS and Logitech, the ATI video
	  adapter mouse, and the Commodore PC30III bus mouse
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0238h"Mouse"

023C  ?W  Command port
023D  ?W  Data port
023E  R?  ID Port