52
ATAPI unit type
Option
Description
Note
None (*)
No unit selected
Default setting for both
ATAPI Units (Master1 &
Slave1)
(*) = Default setting
Auto
Unit auto-detection
LBA
LBA unit selected
CHS
CHS unit selected
CD-ROM
CD-ROM unit selected
Other
Other unit selected
•
Note:
when the
Auto
feature is selected, the BIOS ignores any other data (like Mode, Cyls,
Head, etc.). Use this option for the most of hard disks or other ATAPI devices.
•
Note:
LBA
and CHS are two different types of ATAPI units addressing mode. The first one is
normally used with modern hard disk, from 512 Kbytes to above 8 Gbytes. For both modes
you have to know the
physical hard-disk structure
in terms of Cylinders, Heads and Sectors.
So, for an easy use of any kind of disk, the
Auto
option is preferable.
•
Note:
to speed-up the
bootstrap
select the option
None
for unused ATAPI devices.
PIO Mode
PIO is a special data-transfer system between two or more EIDE devices, where all the data pass
through the processor. There are five transfer rates, called
PIO mode n
(with n=0..4). If the
Auto
(autodetect) option is disabled, the PIO mode must be specified.
Option
Description
Note
PIO-0
Transfer Rate of 3.3 MBps
PIO-1
Transfer Rate of 5.2 MBps
PIO-2
Transfer Rate of 8.3 MBps
PIO-3
Transfer Rate of 11.1 MBps
PIO-4 (*)
Transfer Rate of 16.6 MBps
Default setting for both
ATAPI Units (Master1 &
Slave1)
(*) = Default setting
