From: gowen@sevmsa.cs.msstate.edu
Subject: Docs on adding 2nd HD to A3000.
Organization: Mississippi State University
Date: Thu, 28 Jan 1993 23:39:12 GMT

There have been several requests for the documentation that describes how to
install a second internal hard drive in A3000 computers.  For this reason, I
am reposting that documentation below.

Have Fun!

Lon

******************************* A3000IHD ***********************************
Original Author:  Lon D. Gowen (June 1, 1991)
Revised by:       Lon D. Gowen (January 31, 1992)
Revised by:	  Lon D. Gowen (June 26, 1992)

     This document outlines how to add an additional internal hard drive to an
Amiga 3000 system.  This operation requires one of the A3000's 3.5" bays, which
can hold either a 3.5" floppy drive or a 3.5" hard drive (or any other such
3.5" device).  If your A3000 is already using the two internal floppy-drive
bays, then you cannot apply this update unless you are willing to free up one
bay.  For those people who do not want to free up one bay, I suggest that you
either buy an external SCSI drive or a hard card (i.e., a SCSI controller on an
A3000 compatible expansion card with room for a hard drive on the card).  One
other option may be possible:  stacking two 3.5" drives on top of each other.
This approach, from what I recall, requires the low-profile quantum drives,
which are smaller than normal half-height drives.  Personally, I do not
recommend stacking hard drives in the standard A3000.

     Before explaining this process, you should backup your original hard drive
so that you can rebuild it if necessary.  I also recommend that you read about
the HDToolBox program, which comes with every A3000:  This utility is on the
system disk in the "Tools" directory.  You will use the HDToolBox program to
prepare your new hard drive and at your option check out your original hard
drive.  The HDToolBox program sometimes resets your original disk (depending on
what you do inside the program) to its default partitions, so backup your
original disk.  Also, before you begin, I recommend that you use HDToolBox to
show you your original disk's current partitions (i.e., what their names are,
their boot priority, and their cylinder numbers) since if HDToolBox changes
them, then you can set them back to their original values (if you have that
information written down).  This approach could keep you from having to rebuild
your original disk.  If you back everything up, then you can play with
HDToolBox and have some fun learning how it works.

     The first step, of course, is to obtain the necessary equipment.  You will
need the new hard drive, a Y-cord power cable (for older A3000s), and a 12"
50-pin SCSI ribbon cable (female-female).  You do not need a mounting bracket
since the A3000's floppy mounting bracket works nicely (although not perfectly
on older A3000s).  When you purchase your hard drive, most companies provide a
SCSI cable with the drive but make sure it meets the above specifications.  The
best drive for the price (at least at the time I wrote this) is the Quantum
LP105S, which is a fast (15ms I believe), low-profile, 105 megabyte, SCSI hard
drive.  You can purchase this drive from mail-order houses for about 320
dollars (as of this writing), but the price is sure to drop as time goes on.
The Y-cord power cable is necessary on older A3000s because these A3000s have
only one hard-drive compatible power cable.  The Y-cord power cable converts
the A3000's power cable into two separate power cables; thus allowing the Amiga
to supply power to two internal hard drives.  The 12" 50-pin SCSI ribbon cable
allows you to daisy chain the new hard drive to the A3000's original hard
drive.  This connection is possible because the SCSI interface allows it and
the A3000's internal SCSI cable is a "Y" cable.

                              Parts                           Price
            ================================================  =====
            (1) SCSI hard drive (Quantum LP105S)               $330
            (2) Y-cord power cable (male, female-female)         $3
            (3) 12" 50-pin SCSI ribbon cable (female-female)   free
            (4) Medium-head Phillip's screw driver               ??
                                                              =====
                                                   Total Cost  $333

     The second step is to disconnect everything from your A3000, so you can
install the new hard drive.  This operation is normally very simple - just
unplug all peripherals, set your monitor aside, and move your A3000 chassis to
an empty table where you can work on it.


			 * * * * *  Warning  * * * * *

     The next sections describe the installation process, which involves taking
the cover off your A3000.  Remember that computers are sensitive to static
electricity, so find an appropriate place to work (i.e., a place where you can
discharge static electricity and not pick up anymore).  Avoid touching the
chips inside the A3000, which you should be able to do since this operation
does not add or remove any A3000 chips.  Handle your new and old hard drive
with care and remember that they contain computer chips as well, so try to hold
them by their cases and not by their boards (which are mounted on the drive's
bottom).  Touching computer chips is not bad and perfectly okay so long as you
do not destroy them with static electricity or something else.  Also, while
inside your machine do not drop anything (such as your screw driver) on the
motherboard since scarring the motherboard is bad too.  Well, I think you all
get the idea - treat your machine with care and everything will work out just
fine!  One final note, make sure to remember how everything comes apart, so you
can put your A3000 back together again:  remember what screws go where, what
cables go where, etc.

			 * * * * *           * * * * *
                

     The third step involves removing the A3000's case.  There are five screws
that hold the case to the A3000:  two on the right side, two on the left side,
and one on the back.  Please refer to your A3000 manual titled, "Introducing
the Commodore Amiga 3000" (pages 4-6 and 4-7 in my book) for pictures and a
description of this process.  Remove the screws (making sure to remember where
they came from so you can put them back) and then the A3000's case, which
simply slides off toward the front.

     The fourth step involves removing the internal hard drive that came with
your A3000.  See your manual (pages 4-10 and 4-12) for pictures and a
description of this process.  Before proceeding, you should ground yourself in
order to make sure that you have no static electricity in your body - I
frequently touch the external metal case on the A3000 (not the chips).  Only
one screw holds the internal drive's mounting bracket to the A3000's drive-bay
platform, so remove this screw, carefully slide the drive toward the front to
unhook it from the platform, lift the drive up, and unplug the SCSI and power
cable from the drive.  The manufacturer keyed both cables, so you do not have
to worry about reconnecting them - there is only one way they fit.  At this
point, you have removed the original, internal hard drive from the A3000.  One
warning, be careful when removing the SCSI connector since it may come apart if
you pull on only half of it.  Try to get a good grip on the whole connector and
rock it back and forth until it comes free.

     The fifth step involves moving the 3.5" internal floppy drive from the
left bay area to the right bay area.  Moving the floppy drive allows the two
internal hard drives to be back to back inside the chassis, which in turn
allows the drives and cables to fit neatly inside the case (as you will see
when you complete the installation process).  To move the internal floppy
drive, remove the drive's mounting-bracket screw at the front of the Amiga (see
page 4-11 for pictures).  Next, remove the empty bay's mounting-bracket screw
and the mounting bracket by sliding it toward the case's front.  Now, move the
floppy drive to the right slot, slide it into the platform, and secure its
screw.  Next, move the floppy drive's face plate on the A3000's cover so that
the right bay is open.  The face plate snaps off and on easily.

     The sixth step involves attaching the empty mounting bracket (which you
removed from drive DF1:'s bay area in step five) to the new hard drive.  For
older A3000s (like mine), you will have to attach the drive 2" back on the
mounting bracket since otherwise the drive extends to far toward the case's
front; thus not allowing the case to fit on the A3000 when you are done.  This
means two things:  (1) the new hard drive attaches to the mounting bracket by
using only two screws and (2) the new hard drive will fit very close to the
other hard drive - their backs will be about 2" from each other.  I matched the
back two screw holes on the mounting bracket to the front two screw holes on
the new hard drive; thus, I used only two screws (not four) to secure the hard
drive to the mounting bracket.  If your drive did not come with mounting
screws, you can take two screws from the original hard drive's mounting bracket
since two screws is plenty to hold a hard drive to its mounting bracket.  For
newer A3000s, the mounting bracket fits Quantum drives nicely by attaching to
the drive's side screw holes (not the bottom screw holes).  If your
configuration doesn't match either of these approaches, then try to find the
best fit you can and go with that.

     At this point, the floppy drive should be in the right bay area, which is
in front of the power supply and the normal location for floppy drive DF1:.
Both hard drives should be free from the bay area and have mounting brackets on
their bottom, thus covering most (if not all) of the circuit board.

     The seventh step, for older A3000s, is to get the original hard drive's
power cable up on top of the drive bay area, so you can attach the Y-cord power
cable to it.  Normally the power cable runs under the drive bay and comes back
up toward the A3000's back where it connects to the original internal hard
drive.  Get the power cable on top and attach the Y-cord power cable to it.
After doing this, make sure the other power lines going to the motherboard are
out of your way - you can push them underneath the bay area and out of your
way.  As you can see by now, fitting all the cables inside the case is a
challenging job.

     The eighth step is to configure the SCSI addresses for both internal hard
drives and then set the proper termination.  For Quantum hard drives, you set
the SCSI address using jumpers A0 through A2, which represent a 3-bit binary
number.  These jumpers are near the back, right side of the hard drive as you
look at the drive from the bottom and the back.  To make sure you found them,
you can check the original hard drive, which should have jumpers on A2 and A1
(A0 should be open with no jumper attached to its two pins).  All A3000's come
with the internal hard drive at SCSI address six (in binary %110) while the
SCSI controller is always at address seven and can never change addresses;
therefore, no SCSI device is ever at address seven since the controller
reserves this address for itself.  I do not understand why Commodore set the
internal SCSI address at six when the boot disk (i.e., the original hard drive)
should be at address zero since this allows the machine to boot faster.  I
changed my original hard drive's SCSI address from six to zero by removing all
the jumpers.  I set my new hard drive's SCSI address to one by putting a jumper
on A0 only.  To avoid losing the jumper's caps, you can place them off center
on the jumper's pins so that they connect to only one pin (not both pins).  The
following table outlines the SCSI addresses with the jumpers; a 1 means the
jumper's cap is connected to both pins of the 2-pin jumper while a 0 means the
2-pin jumper is not connected.  One final note, each SCSI drive must have a
unique SCSI address (e.g., you cannot set two drives at SCSI address 1).

                2-Pin Jumpers     SCSI Address
                =============     ============
                  A2  A1  A0        
                  --  --  --
                   0   0   0          ID 0
                   0   0   1          ID 1
                   0   1   0          ID 2
                   0   1   1          ID 3
                   1   0   0          ID 4
                   1   0   1          ID 5
                   1   1   0          ID 6
                   1   1   1        RESERVED

     Now that you have set the SCSI addresses for both drives, you need to make
sure that only the last drive in the internal "SCSI chain" has termination.
For Quantum drives (and most others), the termination resistors are on the
bottom, back part of the drive.  Look for three socketed resistor packs:  mine
are black in color, very thin (about 1/12"), 8/10" long, contain one row of 8
pins, and are labeled F221/331G.  These resistors terminate the last SCSI
device in the daisy chain, so you want to remove them from your original hard
drive and leave them in the new hard drive.  I used a pair of pliers to pull
them out of their sockets.  You should be able to pull them out without using
much force since they are not soldered in place but socketed.

     The ninth step involves putting the original hard drive back into its bay
area (of which you took it from).  Connect the A3000 SCSI cable and one of the
power cables to the original hard drive.  Then, place the hard drive back into
its bay area while making sure the power cables rest on top of the drive (or
someplace else where they are out of the way).  Secure the drive to the bay
area as it was before you removed it (i.e., replace the screw that held the
drive's mounting bracket to the bay area.

     The tenth step involves installing the new drive.  Connect the 12" SCSI
ribbon cable to the new hard drive and daisy chain the other end to the A3000's
SCSI cable near the end of the original internal hard drive.  Then, connect the
other power cable to the new hard drive.  Now slide the new drive into its bay
area, which is where the floppy drive used to be, and secure it there with the
mounting-bracket screw on the machine's front.

     At this point, you should make sure all your cables fit inside the chassis
neatly.  I have the new drive's SCSI cable going over the two power cables and
the top of the original hard drive.  I then fold the excess SCSI cabling
between the two internal hard drives so that the cable lays flat over the
original hard drive and in turn keeps the power cables pinned against the
internal hard drive.  Once everything looks correct, you can replace the
A3000's cover and reconnect your machine.

     The final step!  Turn on your A3000, which should boot up just fine.  If
your A3000 does not come up, then something went wrong (obviously).  Go back
and check all your connects and try again.  If all else fails, feel free to
call me for help.  Now that your Amiga is up and running, you should execute
the program HDToolBox, which is in your Tools drawer (directory) on your system
disk.  See your Commodore manual titled, "Using the System Software" on pages
6-32 through 6-58 (in my manual) for more information on this program.
HDToolBox will come up with a window telling you what SCSI drives are on your
system and their SCSI addresses.  Make sure the SCSI addresses are accurate
with the way you set them.  You will need to have HDToolBox read the drives
information by selecting the new drive (which it probably marked as unknown)
and clicking on the "Change Drive Type" gadget.  HDToolBox will bring up a new
window, and you will want to click on the "Define new drive type" gadget, which
will bring up yet another new window.  Now click on the "Read Configuration
From Drive" gadget, which brings up a nice little window of which you will
click on continue.  At this point, HDToolBox will read all the information
about the new drive and fill in the window with this information.  Now, click
the OK gadget, which should return you to the "Drive Type" window.  Now, select
the drive type that HDToolBox just added to this window and click the OK
gadget, which should return you to HDToolBox's original window.  If you want,
you can do this with your original hard drive too - just to make sure the drive
that is in there is what AmigaDOS thinks it is.  This may sound stupid, but my
Amiga thought it had a 40-megabyte original hard drive when it actually had a
52-megabyte hard drive.  Needless to say, this corrected some strange errors I
was getting.  Next, you need to partition the new hard drive the way you want
it.  I will not describe this process since the manual does a good job, see
pages 6-48 through 6-53 (in my manual).  Once you are done with HDToolBox, you
need to save any changes to the drives in question, which HDToolBox flags as
"Changed."  Once again, the manual describes this process.  After leaving
HDToolBox, format the new drive using the AmigaDOS format command, and you are
ready to go!

*******************************************************************************

     I take no responsibility as to any damage you may cause to your machine.
I am supplying this information so that others can add an additional hard drive
cheaply.  I did not explain every detail, so expect to do some learning by
reading the manuals (as I outlined above).  The whole process is fairly easy
and does not take that much time if you know what you are doing.  Just remember
to take your time, remember how everything came apart so you can put it back
together, and be careful not to damage anything.  Even though this upgrade is
simple, I must state that you try it at YOUR OWN RISK!  I am not liable for any
problems you create.

     Now that I have that out of the way, let me explain some of my problems
that I encountered when doing this project.  First, my machine had problems to
begin with.  After owning my machine for only 1 month, it stopped working - I
could not even boot my machine up.  I took it into a dealer to get it fixed, so
the dealer replaced the original hard drive and my RAM memory, which fixed that
problem.  However, the dealer did not reconfigure my hard drive correctly,
which means that AmigaDOS thought the hard drive was a Quantum P40S when in
fact it was a Quantum LP52S.  In the mean time, my motherboard had intermittent
errors reading and writing data.  I did not notice the problem since everything
worked fine (most of the time).  I did notice Checksum errors pop up every so
often on my hard drive, but I just selected "retry" and everything seemed to
work.  Well, when I added another internal hard drive, my intermittent problem
became much worse.  Large files lost data - I noticed this problem when saving
a large Professional Page document, which I could not then reload since PPage
told me the file was corrupt.  Well, after much pain and checking everything
out with my hard drives, I came to the conclusion that my Amiga 3000 was the
problem and not my hard drives or RAM; therefore, I took my machine in again to
have it fixed.  This time I told them that they would never find the problem
and that I had a "lemon."  I suggested that they replace my whole motherboard,
which to my surprise they did!  For those interested, my old motherboard was
revision 6.1, which you can see printed on the motherboard when you take off
the cover.  My new motherboard, which works just fine with two internal hard
drives, is revision 7.3.  The dealer replaced all my drives and memory
correctly, but failed to set 1 jumper correctly on my motherboard; therefore,
my A3000 thought it had two internal floppy drives when it had only one.  The
small Amiga manual on page E-1 describes all the jumpers, so I just set the
jumper in the correct position and now my A3000 says it has only one floppy
drive (which is correct).

     The moral of this story is that sometimes problems do occur with
computers.  I do not think very many people will have all the problems I did,
but be prepared.  If you have problems that you cannot figure out, I would be
glad to help if I can - just give me a call.  The other lesson is that dealers
sometimes fix one problem and cause others.  I recommend that you check your
machine over whenever a dealer gets done working on it.  Make sure all the
jumpers are in the right places and that your Amiga knows what hard drives it
really has!  Enjoy your Amiga 3000 - I do!


Office:  Lon D. Gowen, Ph.D.
	 Computer Science Department
	 Mississippi State University
	 MS State, MS 39762

         (601) 325-7508
	 e-mail:  gowen@cs.msstate.edu

Home:    Lon D. Gowen
	 2410 Douglas McArthur Drive
	 Starkville, MS 39759
	 (601) 323-6732

P.S.

     Why am I offering to help anyone with Amiga problems?  Well, I like the
Amiga (as most people do), and I know what it is like to have problems without
anyone to help you.  I want to see the Amiga gain ground in the world market,
and I am willing to help anyone that I can in order to achieve that goal.  So,
don't get frustrated, just call another Amiga owner for help (or call me).  I
hope that someday all Amiga dealers will be this willing to help us.  To that
end, I should mention what a super job Joe Cisneros (my old, local dealer) is
doing at Copperstate Computers in Arizona - keep up the good work Joe!


		     * * * * *  Copying Notice  * * * * *

     I give anyone and everyone permission to copy this document so long as
everything stays with the copy (i.e., do not remove anything), so feel free to
distribute this document to BBSs, magazines, friends, newsletters, etc.