PORTIBM PC Portable (uses same BIOS as XT) 03F0-03F1 - PCTech RZ1000 IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself. See also ESDI. controller Note: to unlock access to these ports instead of the standard floppy controller status ports at these two addresses, you must perform two immediately successive 8-bit OUTs of 55h to PORTIBM PC Portable (uses same BIOS as XT) 03F0h (there is a fairly small time limit between the two accesses, so there should be no other instructions between the two OUTs); after that, values written to PORTIBM PC Portable (uses same BIOS as XT) 03F0h select the data accessed through PORTIBM PC Portable (uses same BIOS as XT) 03F1h until an AAh is written to 03F0h SeeAlso: #00732 03F0 ?W index port (see #P0875) 03F1 RW data port (Table P0875) Values for RZ1000 IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself. See also ESDI. controller registers: 00h ??? bit 7: bit 1: bit 0: 01h ??? 02h ??? 03h ??? 04h ??? 05h ??? bit 1: AAh lock control port