Alpha Microsystems SCSI User manual

RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
RIGHT. FROM THE START
SCSI
Disk Drives
Installation Instructions
PDI-00436-20,Rev.A15

1995 Alpha Microsystems
REVISIONS INCORPORATED
REVISION DATE
00 Mar. 1990
01 Apr. 1990
02 May 1991
03 July 1991
04 Aug. 1991
05 Sept. 1991
06 Jan. 1992
07 Apr. 1992
08 July 1992
09 Dec. 1992
10 Jan. 1993
11 Mar. 1993
12 Apr. 1993
13 Sept. 1993
14 Nov. 1993
15 Dec. 1993
SCSI Disk Drives Installation Instructions
To re-order this document, request part number PDI-00436-20.
The information contained in this manual is believed to be accurate and reliable. However, no
responsibility for the accuracy, completeness or use of this information is assumed by Alpha
Microsystems.
This document may contain references to products covered under U.S. Patent Number 4,530,048.
The following are registered trademarks of Alpha Microsystems, Santa Ana, CA 92799:
AMIGOS AMOS Alpha Micro AlphaACCOUNTING
AlphaBASIC AlphaCALC AlphaCOBOL AlphaFORTRAN 77
AlphaLAN AlphaLEDGER AlphaMAIL AlphaMATE
AlphaNET AlphaPASCAL AlphaRJE AlphaWRITE
CASELODE OmniBASIC VER-A-TEL VIDEOTRAX
The following are trademarks of Alpha Microsystems, Santa Ana, CA 92799:
AlphaBASIC PLUS AlphaVUE AM-PC AMTEC
DART ESP MULTI inSight/am
inFront/am
All other copyrights and trademarks are the property of their respective holders.
ALPHA MICROSYSTEMS
2722 S. Fairview Street
P.O. Box 25059
Santa Ana, CA 92799

Page iInstallation Instructions: SCSI Disk Drives
TABLE OF CONTENTS
1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 PRODUCT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3.0 TOOLS REQUIRED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4.0 HANDLING SCSI DISK DRIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
5.0 CONFIGURING YOUR SCSI DISK DRIVE . . . . . . . . . . . . . . . . . . . . . . . . . . 2
6.0 SCSI TERMINATION USING EXTERNAL TERMINATOR OPTION . . . . . . 3
6.1 Termination Procedure (Without External Terminator) . . . . . . . . . . . 4
7.0 TERMINATOR POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.0 SCSI DRIVE INSTALLATION (AM-1400/1600 COMPUTERS) . . . . . . . . . . . 6
8.1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.0 SCSI 3-1/2" DRIVES IN 5-1/4" MOUNTING CONFIGURATIONS . . . . . . . . 7
9.1 3-1/2" SCSI Drives in Series 90 Computers . . . . . . . . . . . . . . . . . . . 10
10.0 ISOLATING SIGNAL AND CHASSIS GROUNDS . . . . . . . . . . . . . . . . . . . . 11
10.1 Testing for AC to DC Ground Shorts Using an Ohm Meter . . . . . . . . 11
10.2 Drive Isolation (AM-1400/1600 Computers) . . . . . . . . . . . . . . . . . . . 13
10.3 Drive Isolation (Pedestal and Rack Mount Computers) . . . . . . . . . . . 14
10.4 Drive isolation (AM-990 Universal VME Enclosure) . . . . . . . . . . . . . 15
11.0 FORMATTING YOUR SCSI DISK DRIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
APPENDIX A - CONFIGURING AMOS SCSI DISK DRIVES
A.1 BOOTING FROM A SCSI DRIVE (AMOS ONLY) . . . . . . . . . . . . . . . A-1
A.1.1 Loading the Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.1.2 SCSI Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
A.1.3 MONGEN the Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
A.1.4 System Initialization Command File . . . . . . . . . . . . . . . . . . . . A-3
A.1.5 Ready to Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
A.2 INITIAL SYSTEM TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
A.3 OTHER DOCUMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
PDI-00436-20, Rev. A15

Page ii Installation Instructions: SCSI Disk Drives
APPENDIX B - AM-436-20 (40MB) AND AM-436-21 (80MB) SCSI DRIVES
APPENDIX C - AM-436-25 (-01) 120MB SCSI DRIVE
APPENDIX D - AM-436-24 (-13) 203MB SCSI DRIVE
APPENDIX E - AM-436-15 (-23) 324MB SCSI DRIVE
APPENDIX F - AM-436-20 (-00) 40MB AND AM-436-21 (-11) 80MB SCSI DRIVES
APPENDIX G - AM-436-20 (-00) 40MB AND AM-436-21 (-11) 80MB SCSI DRIVES
APPENDIX H - AM-436-29 (-19) 234MB AND AM-436-26 (-14) 203MB SCSI DRIVES
APPENDIX I - AM-436-30 (-18) 324MB SCSI DRIVE
APPENDIX J - AM-436-44 1.2GB AND AM-436-45 540MB SCSI DRIVES
APPENDIX K - AM-436-06 (330MB) 5-1/4" SCSI DRIVE
APPENDIX L - AM-436-08 (638MB) 5-1/4" SCSI DRIVE
APPENDIX M - AM-436-08 (638MB) 5-1/4" SCSI DRIVE
APPENDIX N - AM-436-16 (1.2GB) 5-1/4" SCSI DRIVE (PCBA# 1027614)
APPENDIX O - AM-436-16 (1.2GB) 5-1/4" SCSI DRIVE (PCBA# 1027341)
PDI-00436-20, Rev. A15

Page 1Installation Instructions: SCSI Disk Drives
1.0INTRODUCTION
This document describes the installation of both 3-1/2" and 5-1/4" SCSI disk drives into
an Alpha Micro computer. It is written for the experienced Alpha Micro Service
Technician, so if you do not feel comfortable performing the hardware and software
procedures discussed in this document, please contact your Alpha Micro Dealer or the
Alpha Micro Technical Support Group for help.
Installing a SCSI disk drive is simply a matter of placing the drive inside your computer
chassis, connecting the appropriate power and interface cables, and configuring the
correct software. Those wishing to install a SCSI drive into an external subsystem
should refer to the installation instructions for the
AM-1601 Subsystem, PDI-01601-00,
or the
SCSI Universal Subsystem , PGI-00001-00.
This document contains information for each SCSI disk drive currently sold and
supported by Alpha Micro. This information includes drive addressing, terminator
locations, and other items unique to the various drive manufacturers.
2.0PRODUCT DESCRIPTION
The SCSI disk drive package consists of a SCSI disk drive and mounting kit. The
following table shows the storage capacity and the order number for SCSI drives
currently available from Alpha Micro:
DRIVE CAPACITY PART NUMBER
for ordering
213MB PDB-00436-26 (-14)
DRIVE
SIZE
3-1/2"
120MB PDB-00436-25 3-1/2"
1.2GB PDB-00436-44 3-1/2"
540MB PDB-00436-45 3-1/2"
245MB
PDB-00436-29 (-19) 3-1/2"
345MB PDB-00436-30 (-18) 3-1/2"
PDB-00436, (-44), (-45), (-14), (-18), and (-19) 3-1/2" disk drive kits are shipped with a
special 5-1/4" mounting bracket. These kits are applicable for Alpha Micro products that
support 5-1/4" SCSI disk drives, including Series 90 Computers.
PDI-00436-20, Rev. A15

Page 2 Installation Instructions: SCSI Disk Drives
3.0TOOLS REQUIRED
For most installations, the only tools you will need are:
A #2 phillips-head screwdriver.
A pair of needle-nose pliers, used for removing or installing SCSI drive ID
jumpers.
An ohm meter, used to verify the signal ground on the disk drive is not
shorted to chassis ground (not required in Series 90 Applications).
4.0HANDLING SCSI DISK DRIVES
Disk drives can be damaged easily when handled improperly:
1.Leave the SCSI drive in the anti-static bag it was shipped in until you are
ready to install it.
2.Never handle a disk drive unless you are properly grounded. This will
prevent a static charge from damaging the drive before you even have it
installed.
3.Disk drives are extremely sensitive to shock, especially when handled
outside the system environment. When setting a drive on a work bench,
exercise extreme caution; whenever possible try to set the drive on a
padded anti-static surface.
5.0CONFIGURING YOUR SCSI DISK DRIVE
There is a separate appendix for each manufacturer/model of SCSI drive sold and
supported by Alpha Micro in the back of this document. The drives are shown with their
jumpers configured as shipped from the factory. You should carefully go over the
information applicable to the SCSI drive you are installing. The illustrations also
highlight the differences in jumper configurations between AMOS and Series 90
applications. Most of the configuration information shown in the table above each disk
drive is applicable only when the drive is used with the AMOS operating system. The
"number of logicals", "bitmap size", and "format interleave" specifications are not
applicable to Series 90 computers.
SCSI disk drives used in AMOS 680X0 based computers must be installed with the
drive’s signal ground isolated from the computer’s chassis ground. Before installing
your new disk drive, see Section 10 (in this document) dealing with drive isolation in
AMOS based products.
PDI-00436-20, Rev. A15

Page 3Installation Instructions: SCSI Disk Drives
6.0SCSI TERMINATION USING EXTERNAL TERMINATOR OPTION
The preferred method of terminating the SCSI bus in an AMOS based computer is the
installation of an external terminator. In Early April of 1993, the external SCSI bus
terminator became standard on all AMOS based computer configurations. Using an
external terminator makes the task of installing an add-on subsystem (like a portable
CD-ROM drive) easier, eliminating the necessity of removing terminators from a SCSI
device located in the host computer.
External terminators are available from Alpha Micro under part number PRA-00222-00.
To use the external terminator, you need to insure none of your SCSI peripherals inside
the computer are terminated. You will also need to follow the guidelines in the section
on providing termination power for the SCSI bus.
If you have a 10 or 21-slot rack mount VME computer and want to install an external
terminator, you will need to order a special adapter cable, DWB-10200-01. The adapter
cable is required, because there is no external SCSI connector on these computers.
The special cable has a connector that is compatible with the external terminator and
would also allow easy access to your computer for a portable CD-ROM drive or other
SCSI subsystem.
The external terminator is shown in Figure 1:
SCSI
SCSI
(PRA-00222-00)
EXTERNAL SCSI BUS
TERMINATOR
CONFIGURATION B
CONFIGURATION A
BAIL LOCKS
MAC821
#4 SCREW
AND WASHER
Figure 1. External Terminator Installation
PDI-00436-20, Rev. A15

Page 4 Installation Instructions: SCSI Disk Drives
Figure 1 shows two different types of external SCSI connectors.
1.Configuration"A" shows an extended external SCSI connector and bail
locks for holding the terminator in place. This configuration is used on
almost all of Alpha Micro’s currently available product. The terminator is
installed by sliding it over the connector and then latching the bail locks
into the notches in the terminator.
2.Configuration"B" shows a flush mounted external SCSI connector. The
only product Alpha Micro currently offers using a flush mounted external
SCSI connector is the pedestal (also known as the "Classic") chassis. In
this configuration, the terminator inserts into a cutout in the sheet metal
and over the SCSI connector. The terminator is held in place with two
#4screws and washers.
6.1Termination Procedure (Without External Terminator)
1.AM-14XX, AM-16XX, or pedestal computers with one SCSI hard disk drive
can have that hard disk drive installed with its terminators removed.
2.If an AM-14XX, AM-16XX, or pedestal computer has more than one SCSI
device, the last SCSI device, the device attached to the connector farthest
down the cable away from the CPU board must be terminated.
3.If an AM-14XX, AM-16XX, or pedestal computer includes a SCSI magnetic
tape drive as its only SCSI device, the tape drive must have its terminators
installed.
4.For AM-990, 10-slot rack mount VME, and 21-slot rack mount VME
computers, the last SCSI device attached to the connector farthest down
the cable away from the CPU board must have its terminators installed. If
only one SCSI device is installed, that device must be terminated.
5.For subsystem installations, the last SCSI device attached to the
connector farthest down the cable away from the host computer must have
its terminators installed.
AM-1000 and AM-1200 computers follow the same termination procedure used by
AM-14XX, AM-16XX, and pedestal computers.
PDI-00436-20, Rev. A15

Page 5Installation Instructions: SCSI Disk Drives
7.0TERMINATOR POWER
In order to properly terminate the SCSI bus, one of the SCSI peripherals must be
configured to supply termination power to the SCSI bus.
Use the following guidelines to determine which peripheral will be used to supply
termination power for the SCSI bus:
1.Whenever possible, only one SCSI peripheral will be configured to supply
termination power to the SCSI bus.
2.If a computer has more than one SCSI peripheral and at least one of those
peripherals is a disk drive, one disk drive will be configured to supply
termination power to the bus. The other disk or tape SCSI devices will be
configured so they do not supply termination power.
3.If a computer does not have a SCSI disk drive, but does have one or more
SCSI magnetic tape or CD-ROM drives, then one of these devices will be
configured to supply termination power.
4.If a computer with one or more SCSI peripherals is cabled to a subsystem
with additional SCSI devices, one SCSI device in the host computer would
normally be configured to supply termination power for the bus.
You should avoid having a SCSI device in both the host computer and the
subsystem configured to supply termination power. Ideally, you want the
source of the termination power for the bus to be supplied by one power
source.
For information on how to configure terminator power, see the following documents:
 SCSI Disk Drives Installation Instructions, PDI-00436-20, revision A12 or
later.
 AM-625/626/627 SCSI 1/4" Streaming Tape Drive Installation Instructions ,
PDI-00625-00, revision A05 or later.
 AM-647 DAT Tape Drive Installation Instructions, PDI-00647-00, revision
A02 or later.
PDI-00436-20, Rev. A15

Page 6 Installation Instructions: SCSI Disk Drives
8.0SCSI DRIVE INSTALLATION (AM-1400/1600 COMPUTERS)
This section details how to install a replacement 3-1/2" SCSI drive into your AM-1400
or AM-1600 computer. AM-1400 and AM-1600 computers do not require a 5-1/4"
mounting bracket.
SCSI disk drives used in AM-1400/1600 computers must be installed with the drive’s
signal ground isolated from the computer’s chassis ground. Before installing your new
disk drive, see Section 10 (in this document) dealing with drive isolation.
8.1Getting Started
The first step in the installation process is to remove the computer top cover. The top
cover is held in place with four phillips-head screws, two on each side. After you have
removed the screws, lift off the top cover and place it in a safe spot.
The next step is to remove the drive mounting bracket from the chassis. This bracket is
held in place with four phillips-head screws. The screw locations are shown in Figure 2,
called out as A, B, C, and D.
A
B
C
D
DRIVE MOUNTING BRACKET
MAC215
Figure 2
Once you have taken out the screws, remove the drive mounting bracket from the
computer chassis. This will expose the mounting brackets that support the SCSI 3-1/2"
disk drive. The drive is held in place with four screws, two on each side.
Maxtor disk drive product kits include special drive mounting brackets that must be used
for AM-1400/AM-1600 installations. The contents of these kits vary depending on the
drive model. Read the appendix information for the drive you are installing for
information on special brackets and mounting instructions.
PDI-00436-20, Rev. A15

Page 7Installation Instructions: SCSI Disk Drives
If your old SCSI drive is still in place, remove the four screws that attach the drive to the
mounting brackets and remove the drive from the enclosure.
Before installing your new drive, take a look at the mounting brackets that support the
3-1/2" SCSI drive. The brackets should have some insulating material on the inside
edges where the drive and the mounting bracket make contact. The purpose of this
insulating material is to prevent the shorting together of AC and DC grounds through the
drive’s HDA. If your mounting brackets do not have this insulating material, part#
DWF-20526-00, the insulating material is included in drive mounting kits designed for
AM-1400/1600 installations.
Before sliding your new drive into place, make sure the drive is addressed correctly.
Plug the 50-pin interface cable into the drive, making sure the red stripe on the cable
aligns with pin-1 on the drive’s connector. There is a sticker affixed to the top of the
drive’s HDA cover that points to the pin-1 location:
PIN 1 ------>
Plugging the 50-pin interface cable in backwards can damage the drive.
Plug the 4-pin power cable into the drive. This connector is keyed so you can’t go
wrong.
Re-install the top cover.
9.0SCSI 3-1/2" DRIVES IN 5-1/4" MOUNTING CONFIGURATIONS
Most of Alpha Micro’s computers (including Series 90) are designed for 5-1/4" SCSI disk
drives. Alpha Micro has several mounting brackets available that allow a 3-1/2" SCSI
drive to be mounted in 5-1/4" configurations.
SCSI disk drives used in AMOS 680X0 based computers must be installed with the
drive’s signal ground isolated from the computer’s chassis ground. Before installing
your new disk drive, see Section 10 (in this document) dealing with drive isolation.
The PRF-00113-10 bracket, shown at the top of Figure 3, is designed for second drive
applications in AM-1400/1600 computers and AM-1601 subsystems. This bracket is
compatible with both Quantum and Maxtor 3-1/2" drives.
The bracket shown at the bottom of Figure 3 (DWB-00113-20) includes a 5-1/4" front
bezel and is used with Maxtor 3-1/2" drives only. There is similiar bracket available for
Quantum 3-1/2" drives, its part number is PRF-00113-00.
PDI-00436-20, Rev. A15

Page 8 Installation Instructions: SCSI Disk Drives
When ordered as independent demand, the PRF-00113-00 and (-20) mounting brackets
are shipped unassembled. For most applications the 5-1/4" front bezel is not required.
If your application does not require a front bezel, all you need to do is attach the rails to
the drive as shown in Figure 4.
PRF-00113-10 3-1/2" SCSI DRIVE
MOUNTING BRACKET.
PRF-00113-20 3-1/2" SCSI DRIVE
MOUNTING BRACKET.
(INCLUDES FRONT BEZEL)
MAC434
Figure 3 — 5-1/4" Mounting Brackets
PDI-00436-20, Rev. A15

Page 9Installation Instructions: SCSI Disk Drives
A 3-1/2" SCSI drive is installed in the bracket as shown in Figure 4. The drive is held in
place with four screws, two in each side. The illustration shows the drive being mounted
in the DWB-00113-10 bracket, but the procedure is virtually the same for all mounting
brackets.
MAC432
3 1/2" SCSI DISK DRIVE
MOUNTING POSITION
PRF-00113-10 3-1/2" SCSI DRIVE
MOUNTING BRACKET.
Figure 4 — 5-1/4" Mounting Brackets
Once the drive is installed in the bracket, it is compatible with all VME, AM-2000M,
AM-3000M, and AM-960 Series 90 5-1/4" disk drive mounting configurations.
PDI-00436-20, Rev. A15

Page 10 Installation Instructions: SCSI Disk Drives
9.13-1/2" SCSI Drives in Series 90 Computers
Series 90 computers also require 5-1/4" mounting brackets in order to mount 3-1/2"
SCSI disk drives. For Series 90 AM-940, AM-980, and AM-990 computers, the drive is
installed in the bracket as previously described, but the addition of two plastic mounting
rails is required to be Series 90 compatible. These two plastic rails are held in place with
two screws as shown in Figure 5.
Plastic rails are not required for the AM-960 Series 90 computer. Once the drive is
installed in the 5-1/4" mounting frame, it attaches to the AM-960 peripheral mounting
area with four screws, two on each side.
MAC433
3 1/2" SCSI DISK DRIVE
MOUNTING POSITION
HDM-00106-00
MOUNTING RAIL - RIGHT
HDM-00106-01
MOUNTING RAIL - LEFT
Figure 5
Once the rails are installed, the drive slides into place inside your computer chassis.
After the drive is installed in the chassis, install the two metal clips used to keep the
drive from sliding forward from its mounting position.
Plug the 50-pin interface cable into the drive, making sure the red stripe on the cable
aligns with pin-1 on the drive’s connector. There is a sticker affixed to the top of the
drive’s HDA cover that points to the pin-1 location:
PDI-00436-20, Rev. A15

Page 11Installation Instructions: SCSI Disk Drives
PIN 1 ------>
Plugging the 50-pin interface cable in backwards can damage the drive.
Plug the 4-pin power cable into the drive. This connector is keyed so you can’t go
wrong.
10.0ISOLATING SIGNAL AND CHASSIS GROUNDS
For all AMOS 680X0 applications it is important to prevent the disk drive’s DC (signal)
ground from being shorted to the computer’s AC (chassis) ground. Alpha Micro’s SCSI
drive mounting kits contain the necessary hardware used to isolate the drive from
chassis ground. However, you should not be concerned if your drive installation kit
does not contain any of the drive isolation accessories described in the next few
sections. Some disk drives, due to the nature of their design, do not require any
special isolation hardware. You can be certain your drive is properly isolated by using
an ohm meter as described in the next section.
In Series 90 installations, the isolation of signal ground and chassis ground is not
required and is not a problem.
10.1Testing for AC to DC Ground Shorts Using an Ohm Meter
Using an ohm meter is the only way to insure you have properly isolated your disk drive
from chassis ground. We highly recommend that you use an ohm meter to verify
your installation, using the following instructions:
100K
OHMS
0
MAC782
PDI-00436-20, Rev. A15

Page 12 Installation Instructions: SCSI Disk Drives
Checking Individual Peripherals for Shorts to Chassis Ground
1.To determine if a peripheral is shorted to chassis ground, disconnect the
peripheral’s power and interface cables, but do not loosen or remove any
of the peripheral’s mounting hardware. Use an ohm meter to measure
between chassis ground and either of the two middle pins on the
peripheral’s power connector. The power connector has four pins; the two
outside pins are power; the two inside pins are ground.
+5V GND GND +12V
PERIPHERAL DC
POWER CONNECTOR
MAC785
2.If you measure less than 100k ohms between chassis ground and one of
the ground pins on the peripheral’s power connector, you have located a
problem that needs to be corrected. Here are a couple of things to check
for:
a.The four screws attaching the peripheral to its mounting brackets
may be too long. If the screws extend too far into the peripheral they
can come in contact with the peripheral’s signal ground, creating a
direct path to chassis ground.
b.In AM-1400 and AM-1600 computers, if the disk drive mounting
brackets do not have adhesive lexan insulating strips
(DWF-20526-00), it is possible for the drive’s signal ground to be
shorted to the metal mounting brackets.
c.The rotating disks and read/write heads inside your disk drive are
encased in a metal enclosure called the HDA (Head Disk Assembly).
The HDA assembly is tied to the drive’s signal ground. If the HDA
assembly makes metal to metal contact with the drive mounting
brackets in your computer, an AC to DC ground loop may result in
applications where the mounting brackets are directly attached to the
computer’s metal chassis.
d.Review all the mounting procedures discussed in sections 8.X.
There is a separate section for each type of applicable Alpha Micro
computer model.
PDI-00436-20, Rev. A15

Page 13Installation Instructions: SCSI Disk Drives
10.2Drive Isolation (AM-1400/1600 Computers)
In AM-1400 and AM-1600 computers, 3-1/2" SCSI disk drives are installed as described
in Section 6. Unlike most of the other applications, no 5-1/4" mounting bracket is
required for AM-1400/1600 computers.
The disk drive mounting brackets in AM-1400/1600 computer’s have adhesive insulating
strips (DWF-20526-00), that when used in conjunction with nylon screws, prevent the
drive’s signal ground from being shorted to chassis ground. The nylon screws have a
metal insert which greatly increases their strength. See Figure 6.
Some early model AM-1400/1600 3-1/2" drive mounting brackets do not have the
adhesive insulating strips. Therefore, two of the insulating strips are included in drive
installations kits designed for AM-1400/1600 use.
NYLON SCREW
METAL WASHER
METAL INSERT
HDS-11806-04
MAC783
Figure 6. Drive Installation Screw
If you are installing a 3-1/2" drive that is 1-3/4" thick, it is possible for the drive to come
in contact with the chassis bottom. In some cases, by lifting the drive up before you
tighten the mounting screws, you can prevent the drive from making contact with the
chassis bottom. Your success at doing this can be verified with an ohm meter.
Alpha Micro supplies a special isolator (DWF-20525-01) for installing 3-1/2" SCSI drives
thicker than 1". It is a piece of clear mylar designed to completely wrap around the drive.
The isolator has a self-adhesive strip that comes together around the drive as shown in
Figure 7.
PDI-00436-20, Rev. A15

Page 14 Installation Instructions: SCSI Disk Drives
This isolator is used in AM-1400/1600
applications for mounting 1-3/4" thick
3-1/2" SCSI disk drives.
a
a a
a a a a
aa a
aa
aaa
a a
a
a a
a a aa a a
aa
a a a
a
a a
a
aa
a a
a a aa
a a a a
a a
a
a a a a
a a
a a
aa a
a
a a
a
a a
a
a a a
a
a
a a a
a a
a a a a a a a
a aa
a
a a
a
a a
a a
a
a
a a a a a a
a
a a a a
a
a
a
a
a a
a aa
a
Self-Adhesive
Strip
DWF-20525-01
MAC687
Figure 7
The isolator has two sets of holes, allowing both Quantum or Maxtor drives to be used.
Once the isolator is positioned around the drive, it can be placed in its mounting position
inside the chassis. The drive will be held in place using four nylon screws and metal
washers as shown in Figure 6.
10.3Drive Isolation (Pedestal and Rack Mount Computers)
In pedestal and rack mount enclosures, the drive (or drives) sit on a plastic mounting
base and attach to a plastic front bezel; because of the way the drive is mounted, it
would appear to be fully isolated from chassis ground. However, because the front
bezel has a conductive coating, the drive can still be shorted to chassis ground at the
point where it attaches to the front bezel. The use of two nylon shoulder washers
(HDW-10004-07) will insure that the drive will not be able to make electrical contact with
the coating on the front bezel. These washers are used as shown in Figure 8 and install
exactly the same way on both pedestal and rack mount computers.
PDI-00436-20, Rev. A15

Page 15Installation Instructions: SCSI Disk Drives
NYLON SHOULDER WASHERS
(HDW-10004-07)
FRONT BEZEL
METAL SUPPORT BRACKET
DWF-20260-00
SCSI DISK DRIVE
MAC688
Figure 8
10.4Drive isolation (AM-990 Universal VME Enclosure)
Disk drives mount inside the AM-990 chassis using plastic slide rails. One rail installs on
each side of the peripheral. Because the mounting rails are made of plastic, they
prevent the drive from making metal to metal contact with the chassis.
For AM-990 installations, no special drive isolation steps need to be taken.
11.0FORMATTING YOUR SCSI DISK DRIVE
All SCSI drives shipped by Alpha Micro are formatted and ready for use, providing you
are using an Alpha Micro computer running AMOS. If you are installing a SCSI disk
drive into a Series 90 computer, you will need to format the drive before it can be used.
For information on how to format SCSI drives for Series 90 computers, see the
installation instructions shipped with a Series 90 type SCSI controller(s).
If you are installing the drive in a computer booting from AMOS, Appendix A has
instructions on creating drivers; making the drive bootable; and instructions on how to
modify your system initialization command file.
PDI-00436-20, Rev. A15

Page 16 Installation Instructions: SCSI Disk Drives
Under AMOS 2.2 (or later) operating systems, you can divide your hard disk drive into
logical splits larger than 32MB. In fact, you could take a 540MB drive and make it one
giant 540MB logical. While this is perfectly acceptable, you may get a memory allocation
error when running programs that load a copy of the bitmap into your memory
partition—e.g., DSKANA and MONTST. To use these types of programs, you will need
at least one job on your computer with enough memory allocated to allow you to load
the large bitmap. Depending on the size of the logical device, you may need a memory
partition between 100 and 800KB.
PDI-00436-20, Rev. A15