C888-C88F is way out of the allowable range for I/O ports.
00h to FFh is allowed for Motherboard and chipset.
100h to FFFFh is allowed for other devices, BUT any address that uses 4 digits is problematic and very crash prone. 1F0h to 1F7h is the primary IDE, 220h to 233h is the Sound Blaster ports, 378h to 37Fh is the LPT1 ports. FF00h to FFAFh are reserved for system bus interfacing. 3BC to 3BF is noramlly to LPT3 ports. The remainder of the ports 0400 to FEFF are used for stack registers, programming hooks and BIOS links. Reference IBM Hardware interfaces.