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From: cg199ag@icogsci1.ucsd.edu (Steve - Happy Hacker)
Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.ibm.pc.misc,comp.os.msdos.misc
Subject: Installing a Second RLL Hard Disk controller w/ MS-DOS
Keywords: RLL, AT, controller, msdos
Message-ID: <17819@sdcc6.ucsd.edu>
Date: 27 Mar 91 07:18:30 GMT
Article-I.D.: sdcc6.17819
Sender: news@sdcc6.ucsd.edu
Reply-To: cg199ag@icogsci1.ucsd.edu (Steve - Happy Hacker)
Followup-To: comp.sys.ibm.pc.hardware
Organization: University of California, San Diego
Lines: 110
Originator: shaehnic@sdcc13.ucsd.edu
Greetings!
In my never-ending quest for more hard disk space, I am attempting to install
a third and fourth RLL hard disk in my 386. (I had two extra drives, so I
figured buying another controller would be worth it.)
If you want to know what I learn from this article, send me a "Me too!" and
I'll mail you a summary. (or post if interest is high)
Looking at the jumper definitions for my first controller (a WD1006V-SR2),
I saw a setting for "secondary Winchester I/O addresses" and the same for
floppy addresses. Because of this, I bought another WD1006V-SR2 and got it
all installed.
Drives 3 and 4 had to be external, so they got their own power supply and I
fed the ribbon cables out the back of the case. No problem, unless I want
to move my computer. :)
The problem is that both drives are COMPLETELY ignored by my PC. I realize
that they probably won't be found by dos at boot, but I was hoping I could
make them appear by loading a device driver of some kind or informing my
bios. No such luck.
I have not been able to get the actual I/O addresses for this card, but
I know that the XT's was at 320h-323h for the primary and I think 324h-327h
for the secondary controller. If anyone has any for-sure numbers on the AT
cards, (are they the same?) please share them.
Things I have tried to no avail:
- All combinations of BIOS enable/disable on the cards.
This was interesting. If none were enabled, I had to tell my AMI
motherboard BIOS about my 2 hard disks, and it would find the two on
the first controller. This is how I was set up for 2 drives, and never
had any problems with the HD bios disabled. (The HD bios did not have
my correct drive type, the AMI did.)
If both of the controller BIOSes were enabled, the machine would not boot
beyond a point. It would boot OK off of floppy, but could not then find
the hard disks.
If only the first BIOS was enabled, the first two hard drives would work
fine, as soon as I told the AMI bios that I had no HD's installed.
Surprisingly, the exact same thing would happen if I enabled only the
second HDC BIOS. The first two hard disks would run fine.
This all leads me to believe that the BIOS can't be relocated (by
hardware), so as long as one is enabled, it works. Two will fight,
and none will simply not be there. In any case, the BIOS is _not_
finding the second pair of drives. (Neither does the AMI BIOS)
- Calling WD tech support.
I hope it's just me, but in all the times in the past that I have called
WD tech support, they seem to be reading a database, and if your problem
is not in their terminal, they don't know what to tell you other than
"You can't do that."
This answer was no different. He said, "You can never have two 16-bit
hard disk controllers in the same computer." Hmmmm... I would normally
believe the wisdom of tech support, except for that I have SEEN it done.
Interactive Unix has no problem dealing with multiple HD controllers.
When you set it up, it asks you how many hard drives you have, and what
controller each is on. (BTW, it wants all controller BIOSes disabled.)
- Software fixes.
Because Interactive Unix seems to swallow it just fine, I am most
intent on finding a software fix. I need some software BIOS that will
let me set the I/O address of the controller card. I have even
wondered about the possibility of copying the BIOS out of CC000 and
modifying it, but I'm really not up to tweaking assembly code. If anyone
has any similar experiences copying/modifying bioses, please let me know.
DOS's DRIVER.SYS and all the other config.sys variants..
No luck.. they seem to be looking in the same place as dos at boot, and I
doubt they would peek anywhere the BIOS didn't tell them to. Perhaps
they could be modified to use a different HD I/O address?
A nifty utility called MultiDisk (from simtel20) that at first seemed
like the answer to my problems. It correctly claimed to find hard disks
that are ignored, but it did so by looking for a BIOS that was not
automatically extended by DOS. Unfortunately, even if I could relocate
the BIOS, I don't think it would find it's own drives. (It would still
use the same I/O address.) I think this utility was intended more for
old XT's that did not automatically load extension BIOSes. If anyone has
any info that I am missing on this utility, please let me know.
So, that's my problem. I need a driver that will use a hard drive
controller at an address I specify. If you have any pointers or ideas (or
golly, Code!), please drop me a note. Again, Email if you are interested
in doing the same thing, and I'll tell you what I learned.
If it works, it might me a cheap way to turn some of those old drives on
the shelf into some extra storage space!
Thanks very much!
====
-Steve
shaehnic@ucsd.edu -or- shaehnic@ucsd.bitnet
Details:
To make a long story longer, here's my system specs:
Amstrad 386/33 motherboard with 256K SRAM cache
BOCA VGA card (16-bit w/ 1 Meg)
1.2 & 1.44 drives
2 (hopefully 4 soon) RLL hard disks
3 com ports, 1 par, 1 game
7 Meg's of RAM (don't ask)
Sound Blaster
Mars 800 hand scanner
124Meg tape drive (floppy interface)
and power by San Diego Gas & Electric