On 4/25/2020 6:15 PM, Martin Leese wrote:
Hi,

I am transferring an old hard disk (20 Gbyte
Maxtor D740X) from an old PC to a newer one
(Dell Dimension 3000).Â* On the old machine
the disk was the boot drive, and so was
configured as the Master device. On the newer
machine it will be a Slave device.

I have the "Jumper, CHS, and Install Guide"
for the drive, but there are two Slave
jumper settings.Â* These are called "Slave"
and "Slave with AC", but nowhere does the
document explain was "AC" actually is.
(There is also "Master with AC" and "Cable
Select with AC".)Â* What is "AC"?

I can't Google at the moment because my old
PC does not have the required encryption
protocols.Â* This is why I am trying to
upgrade.

I guess so far there's been no explanation of what the "AC" means yet.
My guess is that it probably stands for "Address Control" or something,
which might be a way of getting an older BIOS to understand a newer
drive. I think around this time most drives used the older CHS
(Cylinder, Head, Sector) formatting system, and to get bigger the new
generation had to switch to the newer LBA (Logical Block Address)
system. Address Control might indicate to the BIOS whether to use the
CHS system or the LBA system. Later generation BIOSes could figure this
stuff out on their own.

Yousuf Khan