IBM 2193 Maintenance Service Manual page 55

USB Setup
The options in this menu item are used to enable the USB
(Universal Serial Bus) functions.
USB Controller
Select enabled if you will use USB device.
USB Keyboard Support
Select enabled to use a USB keyboard. Also the USB
Controller must be set to enabled.
IDE Drives Setup
PIO (Programmed Input/Output)
IDE device driver controllers can support up to two separate
drives. These drives have a master/slave relationship which is
determined by the cabling configuration used to attach them to
the controller.
PIO means Programmed Input/Output. Rather than have the
BIOS issue a series of commands to effect a transfer to or from
the disk drive, PIO allows the BIOS to tell the controller what it
wants and then let the controller and the CPU perform the
complete task by themselves. This is simpler and more efficient.
Your system suports five modes, numbered from 0 to 4, which
primarily differ in timing. When Auto(default) is selected, the
BIOS will select the best available mode. This is true for the
next four setup items:
1. IDE Primary Master PIO
2. IDE Primary Slave PIO
3. IDE Secondary Master PIO
4. IDE Secondary Slave PIO
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