Old MFM controller on a PCI bus machine

From: Gordon JC Pearce <gordonjcp_at_gjcp.net>
Date: Tue Jan 27 07:01:07 2004

On Tue, 2004-01-27 at 12:27, Bill Girnius wrote:
> Other than disabling the on board controllers, if memory serves me
> correctly, these boards used an onboard bios to insert the code to fool the
> system to boot to these devices. You very likely need to discover what base
> address the card loads at and make sure that area is reserved in the BIOS as
> in use so nothing is shadowed there. Cards of this era typically used c0000
> or 00000 for their boot code. THe caused problems on newer video cards as
> they wanted the same base IO address space.

You could probably just pull the boot ROM. I'm not sure how Linux
handles MFM and RLL controllers, because I haven't used one for 10 years
or so, but I do know it supports them.

> So basically the IRQ needs to be free, the controller base address needs to
> be free, (I.E. disabling the IDE controller) and the base memory address for
> the onboard bios needs to be available, not only in the CMOS, but also
> ensure no other devices are using it. You may have to dig in your parts bin
> to find an older video card that dosn't grab so many addresses, and possibly
> reconfigure the jumpers on your legacy disk controller to change it base
> address to an unused area.
>

Perhaps you could modify the card to map addresses somewhere else.

Gordon.
Received on Tue Jan 27 2004 - 07:01:07 GMT