[comp.sys.ibm.pc.hardware] Hard drive queries

rdw2030@venus.tamu.edu (WIDRIG, RAQUEL DAWN) (12/06/90)

Some questions...

Is it possible to have more than one hard drive controller in a given system? 
I know you probably can, but all my attempts have failed.  Is it necessary to
use up both "spaces" on the first card before installing a second?

To elaborate a bit, our 386 clone has an IDE card, and I have recently
acquired an MFM drive.  How can I install the MFM and make that drive D?

To further this thing a bit more... I ALSO have another 40 Meg IDE drive that
I want to add to the system.  I can connect both drives to the IDE board, but
the system never will acknowledge the second drive.  I tell SETUP about it 
(both are 40 Meg type 17s) but get the DISK FAILURE error on boot.  When I
go into FDISK and try to select the next drive, I get "Unable to access drive
2" or something like that.

The drive presently in the system is a Conner CP344.  The one I want to add is
a Conner CP342.  I think that the problem may be in the jumper settings, because
the second Conner does not have the jumpers labeled, and there are only three
compared to the four on the first Conner (marked HSP C/D DSP ACT).  On the
second Conner, I have determined which jumper to remove so it isn't treated as
the active drive.  What next?  Does anyone know the settings to help me out?

Once that is solved... we are back to the MFM.  Will I be able to drop in an
MFM controller with the rest of this mess?  This drive is a Seagate ST-251 on
a Western Digital WD1003WAH controller.

Help... I am so frustrated with all this!  Is there an FTP site with some
files describing some of the more difficult aspects of hard drive installation?

Please reply to these questions on the net, as I'm sure others will benefit 
from this.

Thanks a ton!

Mark C. Lowe - KB5III

RDW2030@TAMVENUS.BITNET

cechew@bruce.cs.monash.OZ.AU (Earl Chew) (12/07/90)

In <7982@lanl.gov> rdw2030@venus.tamu.edu (WIDRIG, RAQUEL DAWN) writes:

>Is it possible to have more than one hard drive controller in a given system? 
>I know you probably can, but all my attempts have failed.  Is it necessary to
>use up both "spaces" on the first card before installing a second?

Yes to the first. No to the second.

>To elaborate a bit, our 386 clone has an IDE card, and I have recently
>acquired an MFM drive.  How can I install the MFM and make that drive D?

Hmm... yes... but difficult. The problem is that your BIOS only talks to a
single controller. Your IDE drive is that controller. To install your ST506
(MFM) drive, you will require an ST506 controller (ie another controller).
Furthermore, you must get one such that you can (via jumpers) set it to reside
at the secondary controller address (usually 0x170-0x177 and 0x376 --- from
memory). Most BIOSs (mine in particular [AMI]) don't look at controllers at
that address. One further point, I had to shift the IRQ on the second
controller from IRQ14 to IRQ15. This required surgery in my case (some
controllers are switchable with requiring scalpels). If you don't shift the
IRQ, both controllers drive IRQ14 and get mixed up.

>To further this thing a bit more... I ALSO have another 40 Meg IDE drive that
>I want to add to the system.  I can connect both drives to the IDE board, but
>the system never will acknowledge the second drive.  I tell SETUP about it 
>(both are 40 Meg type 17s) but get the DISK FAILURE error on boot.  When I
>go into FDISK and try to select the next drive, I get "Unable to access drive
>2" or something like that.

>The drive presently in the system is a Conner CP344.  The one I want to add is
>a Conner CP342.  I think that the problem may be in the jumper settings, because
>the second Conner does not have the jumpers labeled, and there are only three
>compared to the four on the first Conner (marked HSP C/D DSP ACT).  On the
>second Conner, I have determined which jumper to remove so it isn't treated as
>the active drive.  What next?  Does anyone know the settings to help me out?

You will have to set jumpers on the second IDE drive so that it thinks it is
the *second* drive. On your original Conner drive I guess that it would be the
C/D jumper. You will have to find out what it is on the second drive.

>Once that is solved... we are back to the MFM.  Will I be able to drop in an
>MFM controller with the rest of this mess?  This drive is a Seagate ST-251 on
>a Western Digital WD1003WAH controller.

Urk... my information on WD1003-WAH controllers leads me to think that this is
difficult. I got hold of a WD1003-WA2. The WA2 allows the IO ports to be moved.
It doesn't allow the IRQ to be moved (that required surgery). You may be able
to find a controller board that allows both IO ports and IRQ to be moved.

I got the following from simtel (wd.arc in the dskutl directory):

     +--LED------------------------------Drive 2-Drive 1-Control--------+
     |  ++J6   +++W6                     ++J3+++ ++J2++ ++++J1++++      |
     |  ++     123          U3           +++++++ ++++++ ++++++++++      |
     |         +++W4       +++++                                        |
     |         123                                 12                   |
     |                                          W1 ++      W5           |
     |                                      +------+ +--+  1+  +--+     | 
     |                                      | U8   | +U9+  2+  +U12     |
     |      WD1003-WAH                      +------+       3+           |
     +-------------------------------+          +--+                +---+
                                     +----------+  +----------------+
     
     Jumper     Position      Function
     
     W1         No Jumper     Status Read is non-latched. Dynamic drive
                              select; i.e. SELECT = DRIVE BUSY. Used for
                              Compaq 286s.
     
                Jumper        Standard Factory Setting. Status Read is
                              latched. Static drive select (SELECT
                              asserted except during RESET). Used for IBM
                              Personal Computer ATs.
     
     W4         Jumper 2-3    Standard factory setting. Ties firmware 
                              sense bit input high.
                Jumper 1-2    Supports 2 head, 612 cylinder second drive
                              with standard system setup for 4 head, 306
                              cylinder drive.
     
     W5         Jumper 2-3    Standard factory setting.
                Jumper 1-2    Internal signal Power-up circuit controls 
                              WG enable.
     
     W6         Jumper 2-3    Standard factory setting. Ties input high.
                Jumper 1-2    Ties input low. The 35 msec step rate cannot
                              be selected with W6 in this position. 
                              Instead, the 16 msec step rate is selected.

As you can see, there's documented jumper (at least according to this
information) that allows you to change IO addresses.

Assuming you manage to drop the board in, you're going to have another
problem. MSDOS talks to disk drives via the BIOS. Your BIOS probably doesn't
know about secondary disk controller addresses (mine doesn't), thus DOS won't
know about it either. To use the drive under DOS you will have to write a
device driver :-(

In case you're interested, here's what I did:

1. Primary disk is IDE. Inherited another disk ST-506 MFM.
   Problem: Existing controller not compatible.

2. Hunt for a controller. Find a WD1003-WA2.

3. Remove IDE drive and controller. Install WA2 and drive (luckily this
   also drives my floppies). Boot floppies, format and check MFM disk.
   All is ok.

4. Set jumpers on WA2 for secondary IO ports. Re-install IDE drive and
   controller. Machine won't boot. Problem: Clashing IRQs.

5. Make new `finger' on WA2 for IRQ15 [probably voids any warranty :-(] and use
   thin insulating tape to cover IRQ14 `finger'. Join IRQ15 and IRQ14
   `fingers'.

6. Machine boots.

7. Give new drive to Minix :-) [I believe that XENIX will also take secondary
   controllers.]

8. Now I have two drives. One IDE drive on an IDE controller, and the other
   an ST506 drive on WD1003-WA2 strapped for secondary IO addresses. My
   floppies run off the IDE controller (which has a built-in floppy controller).
   I suppose I could run two more floppies off the W1003-WA2 controller also.

>Help... I am so frustrated with all this!  Is there an FTP site with some
>files describing some of the more difficult aspects of hard drive installation?

There is some information in the simtel dskutl directory --- but such technical
information as you require is hard to find (I've tried).

Earl
-- 
Earl Chew, Dept of Computer Science, Monash University, Australia 3168
EMAIL: cechew@bruce.cs.monash.edu.au PHONE: 03 5655447 FAX: 03 5655146
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