Old MFM controller on a PCI bus machine

From: Bill Girnius <thedm_at_sunflower.com>
Date: Tue Jan 27 06:27:58 2004

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.

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.


----- Original Message -----
From: "Eelco Huininga" <e.huininga_at_sozawe.groningen.nl>
To: <cctalk_at_classiccmp.org>
Sent: Tuesday, January 27, 2004 4:07 AM
Subject: RE: Old MFM controller on a PCI bus machine

> You could try a BIOS update to see if this works. Also you could try
deactivating the onboard IDE controller since this one usually uses
interrupts 14 and 15.
> Cheers,
> Eelco
> >>> Vintage Computer Festival <vcf_at_siconic.com> 01/26 7:43 >>>
> I haven't played with MFM hard drives and controllers in a LONG time
> (about 10 years now) so I have some questions.
> I'll start off easy. Should there be any reason an old 16-bit ISA MFM
> controller won't work properly in a Pentium-class PC with ISA and PCI
> slots? I imagine I would just have to configure the BIOS to reserve the
> proper interrupt (I believe it's 14, correct?) for the MFM controller.
> I did all this but the MFM controller wreaked havoc on the system. It
> killed the on-board floppy disk and IDE controllers (not physically killed
> but basically disabled them and the system couldn't boot).
> I'm trying to determine if there is a natural conflict before I venture
> forth with this configuration. This may be a problem related to the PC
> I'm trying to plug the card into because there are other oddities with the
> IDE controller that is preventing the system from booting with 4 hard
> drives installed (2 per IDE interface). It halts after it auto-recognizes
> the drives on the primary controller. Weird.
> Anyway, any insight would be appreciated.
> I'm going to do more experimentation in the meantime. I'll get another PC
> with ISA and PCI slots to work with, and will also find an old 386 to test
> the MFM controller on to make sure it is working fine.
> --
> Sellam Ismail Vintage Computer
> --------------------------------------------------------------------------
> International Man of Intrigue and Danger
> [ Old computing resources for business || Buy/Sell/Trade Vintage
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Received on Tue Jan 27 2004 - 06:27:58 GMT

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