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