Subject: Re: No IDE-DMA after sup today ("no driver support")...
To: None <Thilo.Manske@HEH.Uni-Oldenburg.DE>
From: Manuel Bouyer <>
List: current-users
Date: 10/21/1998 08:11:42
On Oct 21, Thilo Manske wrote
> Yes, the drives on the secondary channel *are* *very* *old* ;-)
> (I don't use them ATM.)

Not that old. I have some of them lying around ...
I've got a disk (I think it's MFM) with an ISA controller. It's 30Mb,
and works at about 200Kb/s. It's 5"1/4 make a lot of noise, and can easily
break a foot it it falls from the table. I think this one is
very old :)

> BTW: What das this "compatibility mode" mean?

This means that your controller uses the "standart", compatible ISA I/O ports
and IRQ (0x1f0/0x3f0 irq 14 for primary channel, 0x170/0x370 irq 15 for
secondary). This allow it to work with the standart ISA IDE drivers.
This is a cluge, which need hackery at the PCI/ISA bridge too.
Normal PCI devices are not allowed to use these ports.

It's mostly a BIOS thing, and doesn't have any influence on performances.

Manuel Bouyer, LIP6, Universite Paris VI.