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