From: @arrakis.denver.co.us (Bob Hood)
Newsgroups: alt.msdos.programmer
Subject: Combining MFM and IDE drives
Distribution: world
Date: Thu, 24 Dec 92 04:41:34 GMT
Organization: Bob's Programming Paradise
Reply-To: thor@arrakis.denver.co.us

In article <1992Dec18.095413.27773@cs.kuleuven.ac.be> swa@cs.kuleuven.ac.be writes:
>
> In article <kspousta.724643101@qualcom>, kspousta@qualcom.qualcomm.com (Kevin >  Spousta) writes:
> |> @arrakis.denver.co.us (Bob Hood) writes:
> |>
> |> >I'm not (yet) asking for a method of making it work, I would just like to >  know
> |> >if it is possible to intermix these two hard drive types in the same >  computer.
> |>
> |> YES!  It can be done..  You'll need a special controller for the IDE and >  will
> |> have to boot from the MFM.  (blech!)  Adaptec makes a controller called an
> |> ADP-60L that will read the drive params from an IDE and make it fly.  I use
> |> one of these cards in one of my servers because the thing is so old it won't > |> recognize a 210m drive.  I set the ADP as the secondary controller, the >  drive
> |> type for the 2nd (210m) drive as type 1 and off I go.
> |>
> |> Maybe an MFM controller that'd let you set it up as the secondary controller > |> would work.  Just a thought.
> MS-DOS woudn't find it, even if you cleared all IRQ and adress conflicts.
>
> These is a real cheap solution:
>
> 3drvs110.zip (on an ftp site near you (simtel20 has it))
> shareware $20
>
> You'll need :
>
> MFM controller (the good old one works)
> with 1 or 2 MFM disks !
>
> [...]

Actually, Rich Holland (matt.ksu.ksu.edu!holland) solved the problem quite
nicely.

Here's a copy of Rich's original message and my reply after trying it.  I am 
posting it here for others who might be interested in the solution:

> Yes, it's very posible.  I've got a Seagate ST-157A (42M IDE), and an
> Seagate ST-251-1 (42M MFM) in my 286 clone at home.  Here's what I did:
>
> The 286 has an IDE contorller on the motherboard.  Normal MFM controllers
> won't work, so I bought an ST-21M from seagate.  It's an MFM controller for
> 2 hard drives with a BIOS on board (the ST-22M is the same, but will also
> controll 2 floppies).  I set it up to use the BIOS (don't use the jumper to
> disable it), and changed the address to $D800 (instead of hte default $C800
> which my IDE is using).  I plugged everything in, had to reformat the 251-1,
> and now I've got 2 40 meg drives running perfectly.
>
> The ST-21M was $39 mail order, your mileage may vary.  Feel free to e-mail
> me if you need more help (you can also buy IDE controllers with BIOS on them)

and my reply:

> The card arrived today ($39 from ComputAbility in Milwaukee, WI).
>
> Not only have we been able to add an ST-251, but a 30MB ST-4038 (which is not
> built in to the card's BIOS), and a 40MB Fujitsu M2227D2 out of a Compaq '286
> portable (a non-Seagate hard drive!).
>
> The aforementioned Compaq portable was *non-operational* due to what seems to
> be a BIOS problem.  Plugging the ST-21M into it, and fiddling with the jumper
> settings, BROUGHT IT TO LIFE!  Now it works perfectly (and we got it for
> free because it didn't work!!!).
>
> We are dumbfounded by this card.  It solved a lot of problems in just a few
> hours.  We did find one problem though:  you can't chain more than one MFM
> drive off of it if it is used as a secondary controller.  That is because
> (we surmise) that the computer's BIOS does not support more than two hard
> drive entries, and the IDE already consumes one.  We have not tried using the
> ST-21/22M as the primary controller.
>
> Thanks again, and Merry Christmas!

Bob
--
Bob Hood   thor@arrakis.denver.co.us      H: 303-980-8392   W: 303-623-2180
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                  I'm not an expert, but I play one at work....