PORTIBM PC Portable (uses same BIOS as XT) 0370-0377 - FDC 2 (2nd Floppy Disk Controller) first FDC at 03F0 Note: floppy disk controller is usually an 8272, 8272A, NEC765 (or compatible), or an 82072 or 82077AA for perpendicular recording at 2.88M SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 03F0h-03F7h 0370 R- diskette Extra High Density controller board jumpers (ATIBM PC AT) 0370 R- diskette controller status A (PS/2IBM PS/2, any model, PS/2IBM PS/2, any model model 30) 0371 R- diskette controller status B (PS/2IBM PS/2, any model, PS/2IBM PS/2, any model model 30) 0372 -W diskette controller DOR (Digital Output Register) 0374 R- diskette controller main status register 0374 -W diskette controller datarate select register 0375 RW diskette controller command/data register 0376 RW (2nd FIXED disk controller status/data register) 0377 RW (2nd FIXED disk controller drive address register) 0377 R- diskette controller DIR (Digital Input Register) 0377 -W select register for diskette data transfer rate