Rat said:
You sure? Not all mb's call it IDE mode. Might say enhanced mode or
something like that. My Asus P5K has it and so does my Asrock
Dual-Sata2. I never bother with installing SATA drivers and on my P5K I
only use SATA, including for DVD-RW.
Intel explains what they do, on page 11 here.
http://www.intel.com/design/chipsets/manuals/252671.htm
The default Microsoft driver, understands the I/O mapped option.
IRQ14 and IRQ15 and two drives per ribbon cable, has been
around for a while. And that legacy mode, is all that some
(no longer supported) OSes understand. Some of the first ICH5
motherboards, had settings that allowed flipping to legacy mode,
so a new motherboard could boot Win98 if needed, using nothing
but the Microsoft driver.
The second way to do it (suitable for when more than four disks
are involved), is to move the same interface into the PCI space.
As offsets to a base address register (BAR). There is no longer
a four drive limitation, due to the fixed way the other I/O
mapped thing was set up.
WinXP SP1 has a PCI address space capable driver, to take
care of that "native mode" of operation. Using that, you could
have six hard drives on the ICH5.
Later Intel chipsets seem to have preserved some of those features
(at least if you look at the Southbridge datasheets, they make it
sound like legacy operation is still possible), but the BIOS
presentation may no longer be as friendly or useful.
Paul