S T 3 4 3 7 1 N B A R R A C U D A 4 L SEAGATE
Native| Translation
------+-----+-----+-----
Form 3.5"/SLIMLINE Cylinders 5167| | |
Capacity form/unform 4350/ 5110 MB Heads 10| | |
Seek time / track 8.0/ 0.9 ms Sector/track | | |
Controller SCSI3 SI/ULTRA Precompensation
Cache/Buffer 512 KB MULTI-SEGMEN Landing Zone
Data transfer rate 10.000 MB/S int Bytes/Sector 512
20.000 MB/S ext SYNC
Recording method PRML 0/4/4 operating | non-operating
-------------+--------------
Supply voltage 5/12 V Temperature *C 5 55 | -40 70
Power: sleep W Humidity % |
standby W Altitude km |
idle 9.0 W Shock g |
seek W Rotation RPM 7200
read/write W Acoustic dBA
spin-up W ECC Bit
MTBF h 1000000
Warranty Month 60
Lift/Lock/Park YES Certificates CSA,EEC,EN60950,FCC,IEC950...
**********************************************************************
L A Y O U T
**********************************************************************
SEAGATE ST34371/32171N/ND/W/WD/WC/DC INSTA.GUIDE 77767492, REV.A 3/96
+---------------------------------------------------------+
|1-+ |XX
|| |J6 |XX SCSI
|+-+ |XX I/O
| |XX
| |XX
| |XX
| |XX
| |XX
| |XX
| |XX
| |XX
| |XX
| |XX
| |X1
| |
++LED +---------1 J2 |XX Power
++ +---------+ |XX
+---------------------------------------------------------+ 1
**********************************************************************
J U M P E R S
**********************************************************************
SEAGATE ST32171N/34371N INSTALLATION GUIDE 77767492 REV. A
Jumper Setting
==============
RIGHT SIDE VIEW
BACK +-+ J2 12345678 TOP (HDA) FRONT
OF J1+---------------------P-W-A----------------------- OF
DRIVE +-+ :::::::: BOTTOM DRIVE
||||||||
|Terminator Power +||||||+ Enable T-Res (N models only!)
++Terminator Power -+||||+- Start Delay (12 secs * ID)
| RESERVED --+||+-- Motor Start
| Parity Disable ---++--- Write Protect
|
|
| +----------------------------------------------+
+-+ Termination Power-source Table |
+----------------------------------------------+
|-----....-----....-----PWA edge----- |
| |
| 1 2 1 2 1 2 |
| A Drive Supplies Bus |
| X * * X * * B Drive Supplies Own |
| x * * x xxx C Bus Supplies Drive |
| A B C |
+---------Default------------------------------+
ND drives do not have internal terminators or any other way of
adding internal terminators to the drive; use external active
termination if required.
FRONT VIEW
+--+RESERVED! Shipped with cover installed.
| +Do not remove! Do not install jumpers
TOP (HDA) ++---+ 1
--P-W-A----------------+::::|::::::+--
* BOTTOM +----+123456
| J6 ||||||
LED -+ ||||||
Remote LED +||||+ ID 1
(pin-11 +5V) |||+- ID 2
RESERVED -+++-- ID 4
SCSI ID
-------
+----------+-----------------------+
| SCSI ID | Jumpers |
| | ID4 | ID2 | ID1 |
+----------+-------+-------+-------+
| 0 | OPEN | OPEN | OPEN |
+----------+-------+-------+-------+
| 1 | OPEN | OPEN | CLOSED|
+----------+-------+-------+-------+
| 2 | OPEN | CLOSED| OPEN |
+----------+-------+-------+-------+
| 3 | OPEN | CLOSED| CLOSED|
+----------+-------+-------+-------+
| 4 | CLOSED| OPEN | OPEN |
+----------+-------+-------+-------+
| 5 | CLOSED| OPEN | CLOSED|
+----------+-------+-------+-------+
| 6 | CLOSED| CLOSED| OPEN |
+----------+-------+-------+-------+
| 7 | CLOSED| CLOSED| CLOSED|
+----------+-------+-------+-------+
Use the J6 connector to set the SCSI ID. To change the SCSI ID,
install jumpers on the appropriate pins as shown.
|
---+--------+----------------+-+
| * * * *|* * * * * * * 1 |
| * * * *|* * * * * * * * |J6
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * * * 1 |
| * * * *|* * * * * * * * |J6 SCSI ID 0
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * * * X |
| * * * *|* * * * * * * X |J6 SCSI ID 1
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * * X 1 |
| * * * *|* * * * * * X * |J6 SCSI ID 2
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * * X X |
| * * * *|* * * * * * X X |J6 SCSI ID 3
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * X * 1 |
| * * * *|* * * * * X * * |J6 SCSI ID 4
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * X * X |
| * * * *|* * * * * X * X |J6 SCSI ID 5
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * X X 1 |
| * * * *|* * * * * X X * |J6 SCSI ID 6
+--------+----------------+
---+RESERVED+----------------+
| * * * *|* * * * * X X X |
| * * * *|* * * * * X X X |J6 SCSI ID 7
+--------+----------------+
This drive is a SCAM (SCSI Configured Auto Magically) compliant
drive. If the system into which you are installing this drive
requires SCAM compliant drives you do not need to be concerned about
the drive ID jumper settings, as the system automatically assigns
your new drive the ID it wants it to have. The system may or may not
use the existing drive ID jumper settings.
Before you physically mount your new disc drive in your computer,
you need to check the jumper plug settings that determine how the
drive operates (not true of SCAM compliant systems).
Note that there are some connector pins sticking out from the drive's
printed circuit board (PCB) that are labeled J2 and J6 (called
"jumper plug headers").
Models "W" and "WD" additionally have J1-Auxiliary. Some systems may
have a cable connected to J1-Auxiliary that allows remote setting of
drive ID by switches or within the computer logic. It also provides a
connection to a remote drive activity LED. Jumpers may be used on
J1-Auxiliary.
Note the small jumper plugs connected across pairs of pins in some
places on these connectors.
Note that the jumper plugs used on J2 are shaped differently and are
smaller than those used on J6 or J1-Auxiliary. Do not use J2 plugs on
J6 or J1-Auxiliary as this will damage the internal contacts so they
will not subsequently stay on J2.
The presence or absence of these jumper plugs in various places gives
your drive information about how it is to operate in your system
specifically.
If this is your first hard drive, or if it replaces your existing
hard drive, you may not need to reposition any jumpers. However,
check the figures against your drive to see if it is configured as it
should be for your system. Consult your computer documenta-tion for
information on configuring your drive. Your dealer is the best source
for help on this. Seagate also provides support service for
customers if your dealer can't help.
Set Drive ID
------------
If your system is "SCAM" (SCSI Configured Auto Magically) compliant,
the system assigns the drive ID over the interface, so there is no
need to be concerned about drive ID.
Setting the drive ID jumpers doesn't hurt anything, but is not
necessary.
If your system is not "SCAM" compliant you do need to set the drive
ID using the ID jumpers.
Check your system documentation to see what ID it suggests you give
the drive.
We recommend that if your new drive will be the only hard drive,
assign it as "Drive ID 0," which requires no drive ID jumpers
installed. If your new drive is to be a second hard drive, assign it
as "Drive ID 1" by placing one of the extra jumper plugs supplied in
the enclosed plastic bag (one of the larger plugs) on the "Drive ID
1" position.
Double check drive ID settings for your drive or drives.
Select Operating Features
-------------------------
If your new drive replaces an existing drive, you must set up the new
drive to operate as the old drive did. Check the documenta-tion for
your old drive to see how the drive was set to operate.
Normally, you should leave off the
"Delay Motor Start,"
"Enable Motor Start,"
"Write Protect,"
"Parity Disable," and
"Termpower to SCSI Bus" jumpers. A jumper on means the feature is
enabled, except for "Parity Disable," where a jumper on means that
parity checking is disabled. Only "Terminator Enable" and "Term Power
from drive" jumper positions should have a jumper on ("N" and "W"
models only).
Do not remove these two default jumpers or add jumpers to any of the
other jumper positions mentioned above unless your computer system
documentation indicates otherwise.
Factory installed default settings are generally always correct.
Drive models "WC" and "DC" plug directly into a bulkhead or PCB
mounted connector. Systems using these drives have made provisions
for terminators and selecting most options, so only "Write Protect"
and "Parity Disable" options (on J2) must be considered for possible
setting by a person installing a replacement drive (usually no
change is needed). Most systems using "WC" and "DC" model drives use
drives that have unique drive internal control firmware, so "off the
distributor shelf" drives probably will not work in these
installations. Firmware cannot be changed on these drives. If you are
upgrading by installing an additional drive, consult the system
documentation or system purchase source for help in setting up drive
ID, options, and getting termination correct.
I/O line terminators
--------------------
The SCSI I/O lines must be "terminated" at the drive connected to the
end of the cable. If your new drive is a model "N" or "W" and is to
be connected at the end of the cable.
On J2, the "Terminator Power" (TP) jumper should be left in the
"Term. Power From Drive" position, unless otherwise directed by your
computer documentation.
If your drive is to be connected at the cable connector that is not
at the end of the cable (it is a second hard drive for your system),
the "Terminator Enable" jumper should not be installed. Remove and
store the jumper if there is one on the "Terminator Enable" position.
If your drive is a model "ND" or "WD" and is the last drive at the
end of the cable, an external terminator must be installed between
the I/O cable and the drive.
The external terminator may already be supplied with your system. If
not, one must be purchased at a computer equipment store.
The Terminator you have may not look exactly like the one in the
figure. The "Terminator Power to SCSI Bus" jumper must also be
installed in addition to the "Terminator power from Drive" jumper.
If installing a "WC" or "DC" model drive see system documentation.
These drives have no terminators, nor do they furnish terminator
power to the I/O bus. Terminators are in the Host system.
J2 Terminating the drive
------------------------
+---------------+
--+* * * * * * * 1+-- J2
* * * * * * * *
T D M W P E T T
E S E P D S P P
+---------------+
--+X . . . . . . 1+-- J2 Enable SCSI terminator (default)
X . . . . . . .
+---------------+
--+* . . . . . . 1+-- J2 Disable SCSI terminator
* . . . . . . .
Terminator Power
----------------
There are three posiible terminator power configurations for ST19171N
drives. You will not normally need to change this option and can
leave the drive configured as it was shipped from the factory.
+---------------+
--+. . . . . . X 1+-- J2 Terminator Power from Drive (DEFAUlLT)
. . . . . . X *
+---------------+
--+. . . . . . * X+-- J2 Terminator Power to SCSI Bus
. . . . . . * X
+---------------+
--+. . . . . . * 1+-- J2 Terminator Power from SCSI BUS
. . . . . . xxx
Other applicable jumper options
-------------------------------
+---------------+
--+. . . . . * . 1+-- J2 RESERVED
. . . . . * . .
Delay Motor Start option
------------------------
Delay Motor Start option (valid only if the Enable Motor Start
jumper is not connected)
+---------------+
--+. * . . . . . 1+-- J2 Disable the Delay Motor Start option
. * . . . . . . (default)
+---------------+
--+. X . . . . . 1+-- J2 Motor start delay equal to the SCSI ID
. X . . . . . . multiplied by 12 seconds. For example, if
the SCSI ID = 2, the drive starts in 24
seconds.
Motor Start option
------------------
+---------------+
--+. . * . . . . 1+-- J2 Disable motor start (default). The drive
. . * . . . . . starts according to the Delay Motor Start
Option.
+---------------+
--+. . X . . . . 1+-- J2 Enable motor start. The drive waits for the
. . X . . . . . Start Unit command from the host before
starting the spindle motor.
Write Protect Option
--------------------
+---------------+
--+. . . * . . . 1+-- J2 Write protect = OFF (enables writing -
. . . * . . . . default)
+---------------+
--+. . . X . . . 1+-- J2 Write protect = ON (disables writing)
. . . X . . . .
Parity Check Option
-------------------
+---------------+
--+. . . . * . . 1+-- J2 Enables parity check of SCSI bus (default)
. . . . * . . .
+---------------+
--+. . . . X . . 1+-- J2 Disables parity check
. . . . X . . .
**********************************************************************
I N S T A L L
**********************************************************************
SEAGATE ST34371/32171/N/ND/W/WD/WC/DC INSTA.GUIDE 77767492 REV.A 3/96
Notes On Installation
=====================
Installation direction
----------------------
horizontally vertically
+-----------------+ +--+ +--+
| | | +-----+ +-----+ |
| | | | | | | |
+-+-----------------+-+ | | | | | |
+---------------------+ | | | | | |
| | | | | |
| | | | | |
+---------------------+ | +-----+ +-----+ |
+-+-----------------+-+ +--+ +--+
| |
| |
+-----------------+
The drive will operate in all axis (6 directions).
Drive configuration
-------------------
You can easily install your new Seagate disc drive as your first ever
hard drive, a replacement or as a second drive in a computer system
with an existing hard disc drive.
Installation
involves the following steps:
- Drive configuration
- Mounting
- Informing the computer about your drive and how you want it divided
into partitions.
Note
This drive is a SCAM (SCSI Configured Auto Magically) compliant
drive. If the system into which you are installing this drive
requires SCAM compliant drives you do not need to be concerned about
the drive ID jumper settings, as the system automatically assigns
your new drive the ID it wants it to have. The system may or may not
use the existing drive ID jumper settings.
Before you physically mount your new disc drive in your computer,
you need to check the jumper plug settings that determine how the
drive operates (not true of SCAM compliant systems).
I/O line terminators
--------------------
The SCSI I/O lines must be "terminated" at the drive connected to the
end of the cable. If your new drive is a model "N" or "W" and is to
be connected at the end of the cable. On J2, the "Terminator Power"
(TP) jumper should be left in the "Term. Power From Drive" position,
unless otherwise directed by your computer documentation.
If your drive is to be connected at the cable connector that is not
at the end of the cable (it is a second hard drive for your system),
the "Terminator Enable" jumper should not be installed. Remove and
store the jumper if there is one on the "Terminator Enable" position.
If your drive is a model "ND" or "WD" and is the last drive at the
end of the cable, an external terminator must be installed between
the I/O cable and the drive.
The external terminator may already be supplied with your system. If
not, one must be purchased at a computer equipment store and
installed.
The "Terminator Power to SCSI Bus" jumper must also be installed in
addition to the "Terminator power from Drive" jumper.
If installing a "WC" or "DC" model drive see system documentation.
These drives have no terminators, nor do they furnish terminator
power to the I/O bus. Terminators are in the Host system.
Mounting the drive
------------------
Important Precautions:
- Make sure your computer is turned off before beginning
installation.
- Although switched off, your computer must remain plugged into an
electrical outlet with an earth ground. This minimizes the
possibility of damage from static discharge.
- Static electrical charges can accumulate quickly on people,
clothing and synthetic materials. The electrostatic fields due to
these charges when brought in close proximity to susceptible
circuit assemblies and components, can result in degraded
reliability or immediate failure of the affected component or
assembly.
- Always wear a grounded wrist strap. Attach the wrist strap to the
metal chassis of your computer. Use the antistatic pad as your work
surface, and avoid installation in areas with static-inducing
carpets.
1. Begin by removing the cover of the computer. Follow the
instructions in your computer manual. Systems that use "WC" and
"DC" drives probably do not require cover removal, as the drives
are mounted in a module that slides into place and plugs in.
2. Connect the 50 or 68 pin interface cable to the hard drive
interface connector on the SCSI host adapter card. Be careful not
to bend the pins on the host adapter card connector. Refer to your
SCSI host adapter manual for the location of the interface
connector.
The sockets on the interface cable must be matched correctly with
the pins on your SCSI host adapter interface connector. Verify the
location of pin 1 on the SCSI host adapter using your computer
system's manual. Pin 1 on the interface cable is indicated by the
stripe along the edge of the cable. Plug the cable into the hard
drive interface connector on your SCSI host adapter.
3. Thread the other end of the interface cable through your drive bay
and connect to the disc drive.
The sockets on the interface cable must be matched correctly with
the pins on the disc drive. Pin 1 on the interface cable is
indicated by the strip along the edge of the cable; pin 1 on the
Seagate disc drive is the pin closest to the HDA, on the side
closest to the four-pin power supply connector.
Plug the interface cable into the drive connector firmly
but carefully. The connector should cover both rows of pins.
If you are installing a second or multiple disc drives, repeat
this procedure using the additional drive connectors on the
interface cable.
4. Mount the drive in a drive bay.
- Direct mounting: The disc drive can be mounted in the drive bay in
any orientation permitted by the drive bay mechanical
configuration. Be careful not to over tighten the mounting screws.
Screws must not extend into the side drive mounting holes more than
0.015 inches, (9/64 inches) or into the bottom mounting holes 0.20
inches (3/16 inches). Purchase the four required 6-32 x 1/4 inch
screws at a hardware or drive supplier store.
- Using a special module: "WC" and "DC" drives should be fitted
with slides or most likely, mounted in a special module that
slides into the host equipment.
- Drive activity LED: If the drive mounts such that the drive
activity LED does not show when the computer cover is on, the
computer may provide for a remote LED two conductor cable to be
used on all models. This cable plugs into J6 on the front of the
drive.
"WC" and "DC" model drives have a line available in the J1-80 pin
interface. Check system documentation to see if J1 signal is used or
if a cable should be attached to J6.
5. Attach a system power cable to the power connector on each drive.
If your system does not have an extra power cable for the hard
drive, you can purchase a Y-shaped power cable.
6. Review each of the previous steps to verify that you have
completed the installation correctly.
7. Replace the cover on your computer.
**********************************************************************
F E A T U R E S
**********************************************************************
SEAGATE ST34371/32171N/ND/WD/W/WC/DC INSTAL.GUIDE 77767492 REV.A 3/96
Safety instructions
-------------------
1. The disc drive is to be installed in a customer supplied enclosure
where the surrounding air does not exceed 50*C.
2. Four (4) 6-32 UNC-2A screws are required for installation. Maximum
screw length into side of drive is 0.15 inches (9/ 64 inch) (3.81
mm). Maximum screw length into bottom is 0.20 in. (3/16 inch)
(5.08 mm). Screw tightening torque is 6.0 lb-in (.675 NM) max with
minimum thread engagement of 0.12 in (1/8 inch) (3.00 mm).
3. The power requirements are shown in the Product Information
section.
4. The power supply must satisfy the safety requirements for SELV
(Safety Extra Low Voltage) circuits.
5. Service is to be provided by trained Seagate service personnel.
6. The incorporation of the disc drives listed in this guide into a
customer enclosure must meet the appropriate safety requirements
of the country in which it is used (e.g. UL 1950, CAN/CSA-C22.2
No. 950-M89, DIN VDE 0805:1993 and EN60950: 1992 (IEC 950).
Note
Power must be off when connecting or disconnecting.
Configuring the computer for your drive
---------------------------------------
The hardware part of your installation should now be complete.
Software installation informs your computer operating software about
your Seagate disc drive characteristics. You can then divide your
drive into partitions called "logical drives", if you want to,
although this is not necessary.
If you already have a hard disc drive on your computer and you are
installing a second drive, now is a good time to evaluate the status
and quality of your backups. Once you are satisfied with the status
of your backups, then proceed.
Note!
Seagate Technology assumes no responsibility for lost user data.
DOS Installation
----------------
To install your Seagate disc drive in your computer software, consult
your computer operating system documentation for assistance. Your
SCSI adapter card must be able to address the capacity of this drive.
Macintosh installation
----------------------
To configure this drive in a Macintosh system, you must use a
third-party hard disc initialization application. Most software
vendors and computer stores that carry Macintosh software will have
hard disc drivers available for purchase.
Follow the instructions provided with the disc initialization
application to complete the installation of your Seagate drive.
Note.
The Apple HD SC Setup utility included with your Macintosh system
software only works on drives ordered directly through Apple.
Unix installation
-----------------
There are several versions of the Unix operating system. Each of
these handle hard disc installation in a different manner. For this
reason, refer to your system's operation manual for information
about how to complete the installation of this disc drive. Contact
Seagate Technical support services for any additional information
needed to install the drive in a Unix system.
Other operating systems
-----------------------
Check your system documentation for instructions on installing new
drives.
**********************************************************************
G E N E R A L
**********************************************************************
SEAGATE SCSI
Interface requirements
----------------------
How to use this interface manual
This specification is designed to provide a universal detailed
description of the SCSI interface for those disc drive products whose
Product Manuals (Volume 1) do not contain the details of how the
SCSI interface is implemented by that drive.
Note: Volume 1 Product Manuals have tables in Section 11 that specify
which SCSI-1 or SCSI-2/SCSI-3 features they implement, what the
default parameters are for the various features they implement and
which parameters are changeable and which are not. No method exists
at present to inform an initiator if a target supports "SCSI-3"
features as opposed to only SCSI-2 features. A few "SCSI-3" features
are supported by Seagate drives, but no attempt has been made herein
to differentiate between SCSI-2 and "SCSI-3" features. Therefore,
when an Inquiry command reports what the ANSI approved version of the
drive is, it reports either SCSI-1 or SCSI-2, where "SCSI-2" means
SCSI-2 features plus some "SCSI-3" features.
No attempt is made in this universal specification to specify which
descriptions or tables apply to SCSI-1 and which to SCSI-2 or SCSI-3.
The combination of this general specification with the details in
the Section 11 tables of the individual drive Product Manual (Volume
1) provides a description of the individual drive implementation of
the SCSI interface. This interface manual is not intended to be
stand-alone text on SCSI-1 or SCSI-2/SCSI-3 features.
Reference must be made back to the individual drive Product Manuals
to find out what are SCSI-1 and what are SCSI-2/SCSI-3 features.
This specification is Volume 2 of a set of manuals that is made up of
separate drive Product Manuals (Volume 1) and this manual. This
Volume 2 Manual is referenced by other Volume 1 Product Manuals
representing the drives listed below.
Product Manuals for the following models reference this volume:
ST11200N/ND/NC, ST1980N/ND/NC, ST1830N, ST1950N, ST3500N, ST3600N,
ST3610N/ND/NC, ST12400N/ND/NC, ST12400 Wide, ST11900N/ ND/NC,
ST31200N/ND/NC, ST31200 Wide, ST11950N/ND, ST11950W/WD,
ST12450W/WD, ST12550N/ND, ST12550W/WD, ST15150N/ND, ST15150W/WD,
ST3655N, ST3550W, ST3390N and ST3285N, ST32430N/ND/NC,
ST32430W/WD/WC, ST15230N/ND/NC, ST31250N/ND, ST31250W/WD/WC,
ST32151N, ST31051N, ST32550N/ND, ST32550W/WD/WC, ST3471N,
ST410800N/ND, ST410800W/WD.
General interface description
-----------------------------
This Product Manual describes the Seagate Technology, Inc. subset of
the SCSI (Small Computer Systems Interface) as implemented on the
Seagate built disc drives listed above. The interface is compatible
with the SCSI Interface Specifications of the ANSI SCSI-1 standard,
the ANSI SCSI-2 Standard and the common command set (CCS) document,
Revision 4.B. The disc drives covered by this Product Manual are
classified as "Intelligent" peripherals.
The Seagate SCSI interface described herein consists of a 9 or 18 bit
bidirectional bus (8 data + 1 parity or 16 data + 2 parity) plus 9
control signals supporting multiple initiators, disconnect/
reconnect, self configuring host software, automatic features that
relieve the host from the necessity of knowing the physical
architecture of the target (logical block addressing is used), and
some other miscellaneous features.
The SCSI physical interface uses either single ended drivers and
receivers or differential drivers and receivers and uses asynchronous
or synchronous communication protocols. The bus interface transfer
rate for asynchronous or synchronous is given in individual disc
drive Volume 1 Product Manuals. The bus protocol supports multiple
initiators, disconnect/reconnect, additional messages plus 6 byte and
10 byte Command Descriptor Blocks. Unless specified otherwise in the
individual drive Product Manuals (Vol. 1), the disc drive is always a
target, and never an initiator. For certain commands, which may or
may not be supported by a particular drive model, the drive must act
as an initiator, but does not otherwise do so. For purposes of this
specification, "disc drive" may be substituted for the word "target"
wherever "target" appears.
GLOSSARY
--------
Arbitration - SCSI bus phase wherein SCSI devices try to gain control
of the SCSI bus to operate as an initiator or target
Byte - This term indicates an 8 bit hexadecimal construction.
Command Descriptor Block (CDB) - The structure used to communicate
requests from an initiator to a target.
Connect - The function that occurs when an initiator selects a target
to start an operation.
Disconnect - The function that occurs when a target releases control
of the SCSI bus, allowing it to go to the Bus Free phase.
FRU (Field Replaceable Unit) - An assembly that is believed faulty
based on test results. A value of 00h indicates an unknown cause or
the end of a list of known possible causes. Nonzero values have
product unique meanings.
Initiator - A SCSI device (usually a host system) that requests an
operation to be performed by another SCSI device.
Intermediate Status - A status code sent from a target to an
initiator upon completion of each command, except the last command,
in a set of linked commands.
I/O Process - An I/O process consists of one initial connection and
zero or more reconnections, all pertaining to a single command or
group of linked commands. More specifically, the connection(s)
pertain to a nexus as defined below in which one or more command
descriptor blocks are usually transferred. An I/O process begins with
the establishment of a nexus. An I/O process normally ends with the
BUS Free phase following successful transfer of a COMMAND COMPLETE,
ABORT, ABORT TAG, or CLEAR QUEUE message. An I/ O process also ends
when a hard RESET condition occurs, an unexpected BUS FREE phase
occurs, or when the BUS FREE phase occurs following a BUS DEVICE
RESET message.
I T nexus - A nexus prior to the successful receipt of an IDENTIFY
message, at which time the nexus is changed to an I T L nexus. (See
glossary word "Nexus").
I T L nexus - A nexus that exists between an initiator and a Logical
Unit. This relationship replaces the prior I T nexus. (See glossary
word "Nexus").
I T L Q nexus - A nexus between an initiator, a Logical Unit, and a
queue tag following the successful receipt of one of the QUEUE
messages. This relationship replaces the prior I T L nexus. (See
glossary word "Nexus").
Logical Unit - A physical device or virtual device addressable
through a target. The disc drive is a target but also a Logical Unit.
Logical Unit Number - An encoded three bit identifier for the logical
unit. The disc drive is considered Logical Unit number zero.
LSB - Least significant byte
MSB - Most significant byte
ms - millisecond
LUN - Logical unit number
mm - Millimetre
SCSI bus
--------
This manual discusses only the "logical" and timing characteristics
of the SCSI system and interface. The SCSI bus physical
characteristics (voltages, connector configurations, pinouts, etc.)
are given in the individual disc drive Product Manuals (Volume 1)
Section "Interface requirements", which covers all of the interface
requirements and SCSI features supported by the drive described in
the particular Product Manual being referenced.
Communication on the SCSI Bus is allowed between only two SCSI
devices at a time. Some Seagate drives support systems with a maximum
of eight SCSI devices including the host computer(s) connected to the
SCSI bus. Some Seagate drives support systems with a maximum of
sixteen SCSI devices on the SCSI bus. Each SCSI device has a SCSI ID
Bit.
The SCSI ID is assigned by installing from 0 to 3 (8 device systems)
jumper plugs or 0-4 (16 device systems) jumper plugs onto a connector
in a binary coded configuration during system configuration. Some
drive models have an interface that includes the SCSI bus ID lines,
so that the host can set the drive ID over the interface. See
individual disc drive Product Manual, Section "Option/configuration
headers".
When two SCSI devices communicate on the SCSI Bus one acts as an
initiator and the other acts as a target. The initiator (typically a
host computer) originates an operation and the target performs the
operation. The disc drive always operates as a target, unless
specified otherwise (i.e., certain commands are supported) in the
individual drive Product Manual.
The Host Adapter/Initiator must be identified by one of the eight
SCSI Device Addresses. Make sure that none of the devices on the SCSI
bus have duplicate addresses. Certain SCSI bus functions are assigned
to the initiator and certain SCSI bus functions are assigned to the
target. The initiator will select a particular target. The target
will request the transfer of Command, Data, Status or other
information on the data bus.
Information transfers on the data bus are interlocked and follow a
defined REQ/ACK Handshake protocol. One byte of information will be
transferred with each handshake. Synchronous data transfers do not
require a one for one interlocking of REQ/ACK signals, but the total
number of REQ pulses in a particular data transfer event must equal
the total number of ACK pulses.
The disc drive supports single initiator, single target; single
initiator, multiple target; multiple initiator, single target; or
multiple initiator, multiple target bus configurations.
SCSI bus signals
----------------
There are ten control and eighteen data signals, as listed below:
- BSY
- C/D
- MSG
- DIFFSENS
- SEL
- I/O
- REQ
- DB(7-0, P); DB(15-8,P1)
- ACK
- ATN
- RST
Some drive models have a single 80 pin I/O connector that contains
additional interface lines that carry drive configuration select
signals. These are peculiar to certain drives and are not SCSI
standard signals. These are described in the drive model's Volume 1
Product manual, but not here. The 28 SCSI standard signals are
described as follows:
BSY (Busy) - An "OR-tied" signal to indicate the bus is being used.
SEL (Select) - A signal used by an initiator to select a target, or
by a target to reselect an initiator.
C/D (Control/Data) - A signal driven by a target to indicate whether
Control or Data information is on the Data Bus. Assertion indicates
Control.
I/O (Input/Output) - A signal driven by a target to control the
direction of data movement on the Data Bus with respect to an
initiator. Assertion indicates input to the initiator. This signal
also distinguishes between Selection and Reselection phases.
MSG (Message) - A signal driven by a target during the Message phase.
REQ (Request) - A signal driven by a target to indicate a request for
REQ/ACK data transfer handshake.
ACK (Acknowledge) - A signal driven by an initiator to indicate an
acknowledgment for a REQ/ACK data transfer handshake.
ATN (Attention) - A signal driven by an initiator to indicate the
Attention condition. It is used to request to send a message out to
the target. If an initiator asserts ATN while asserting SEL it
indicates to the target that the initiator supports messages other
than command complete.
RST (Reset) - An "OR-tied" signal that indicates the Reset condition.
DIFFSENS (Differential Sense) - When the drive has differential SCSI
I/O circuits, the DIFFSENS signal disables the drive s differential
driver/receiver circuits if the SCSI I/O cable is plugged in upside
down, or if a single-ended SCSI I/O cable is plugged into a
differential I/O drive. Disabling the differential I/O drivers/
receivers is necessary to prevent burning them out if a grounded I/O
line is connected to any of the differential circuit outputs, which
are at a positive voltage (+2 V or +3 V) when not disabled.
DB(7-0,P) and DB(15-8,P1)
(Data Bus) - Sixteen data bit signals, plus parity bit signals form a
Data Bus. DB(7) is the most significant bit and has the highest
priority during the Arbitration phase (on both eight and sixteen
device systems). Bit number significance, and priority decrease
downward to DB(0), and then from DB15 down to DB8 (DB0 is higher than
DB15). A data bit is defined as one when the signal is asserted and
is defined as zero when the signal is negated.
Data parity DB(P) and DB(P1) is odd - The use of parity is a system
option. The disc drive always checks parity on the data bits, but has
the capability to enable/disable parity error reporting to the host.
See configuration selection in the applicable Product Manual. Parity
checking is not valid during the Arbitration phase.
Greater detail on each of the SCSI Bus signals is found in the
following sections.
Drive Select
------------
For SCSI ID selection install drive select jumpers as shown in
configuration selection figure in applicable Product Manual. Refer to
section 10 of the individual drive Product Manual for the location
of the drive select header. The disc drive using the eight bit data
interface can have one of eight ID bits selected by installing 0 to 3
jumpers in a binary coded configuration on the drive select header.
Drives using the 16 bit data interface can have one of sixteen ID
bits selected by installing 0 to 4 jumpers in a binary coded
configuration on the drive select header.
Signal Values
-------------
Signals may assume true or false values. There are two methods of
driving these signals. In both cases, the signal shall be actively
driven true, or asserted. In the case of OR-tied drivers, the driver
does not drive the signal to the false state, rather the bias
circuitry of the bus terminators pulls the signal false whenever it
is released by the drivers at every SCSI device. If any driver is
asserted, then the signal is true. In the case of non-OR-tied
drivers, the signal may be negated. Negated means that the signal may
be actively driven false, or may be simply released (in which case
the bias circuitry pulls it false), at the option of the implementor.
OR-Tied signals
---------------
The BSY and RST signals shall be OR-tied only. In the ordinary
operation of the bus, these signals are simultaneously driven true by
several drivers. No signals other than BSY, RST, and DB(P) are
simultaneously driven by two or more drivers, and any signal other
than BSY and RST may employ OR-tied or non-OR-tied drivers. DB(P)
shall not be driven false during the Arbitration phase. There is
no operational problem in mixing OR-tied and non-OR-tied drivers on
signals other than BSY and RST.
Signal sources
--------------
All SCSI device drivers that are not active sources shall be in the
passive state. Note that the RST signal may be sourced by any SCSI
device at any time. The disc drive functions as a target.
Nonarbitrating system
---------------------
In systems with the Arbitration phase not implemented, the initiator
shall first detect the Bus Free phase and then wait a minimum of a
bus clear delay. Then, except in certain single initiator
environments with initiators employing the single initiator option
the initiator shall assert the desired target's SCSI ID and its own
initiator SCSI ID on the Data Bus. After two deskew delays, the
initiator shall assert SEL.
Arbitrating systems
-------------------
In systems with the Arbitration phase implemented, the SCSI device
that won the arbitration has both BSY and SEL asserted and has
delayed at least a bus clear delay plus a bus settle delay before
ending the Arbitration phase. The SCSI device that won the
arbitration becomes an initiator by releasing I/O. Except in certain
single initiator environments with initiators employing the single
initiator option, the initiator shall set the Data Bus to a value
which is the OR of its SCSI ID bit and the target s SCSI ID bit. The
initiator shall then wait at least two deskew delays and release
BSY. The initiator shall then wait at least a bus settle delay before
looking for a response from the target.
All systems
-----------
In all systems, the target shall determine that it is selected when
SEL and its SCSI ID bit are true and the BSY and I/O signals are
false for at least a bus settle delay. The selected target will
examine the Data Bus in order to determine the SCSI ID of the
selecting initiator unless the initiator employed the single
initiator option. The selected target shall then assert BSY within a
selection abort time of its selection; this is required for correct
operation of the timeout procedure. In systems with parity
implemented, the target shall not respond to a selection if bad
parity is detected. Also, if more than two SCSI ID bits are on the
Data Bus, the target shall not respond to selection. At least two
deskew delays after the initiator detects BSY is asserted, it shall
release SEL and may change the Data Bus.
Single initiator option
-----------------------
Initiators that do not implement the Reselection phase, and do not
operate in the multiple initiator environment, are allowed to set
only the target's SCSI ID bit during the Selection phase. This makes
it impossible for the target to determine the initiator s SCSI ID.
Selection time out procedure
----------------------------
A Selection timeout procedure is specified for clearing the SCSI bus.
If the initiator waits a minimum of a selection timeout delay and
there has been no BSY response from the target, the initiator shall
continue asserting SEL and shall release the Data Bus. If the
initiator has not detected BSY to be asserted after at least a
selection abort time plus two deskew delays, the initiator shall
release SEL allowing the SCSI bus to go to the Bus Free phase. SCSI
devices shall ensure when responding to selection that the selection
was still valid within a selection abort time of their assertion of
BSY. Failure to comply with this requirement could result in an
improper selection (two targets connected to the same initiator,
wrong target connected to an initiator, or a target connected to no
initiator). The disc drive supports systems that implement this
procedure.
Asynchronous information transfer
---------------------------------
The target shall control the direction of information transfer by
means of the I/O signal. When I/O is true, information shall be
transferred from the target to the initiator. When I/O is false,
information shall be transferred from the initiator to the target.
If I/O is true (transfer to the initiator), the target shall first
drive DB(7-0,P)* to their desired values, delay at least one deskew
delay plus a cable skew delay, then assert REQ. DB(7-0,P)* shall
remain valid until ACK is true at the target. The initiator shall
read DB(7-0,P)* after REQ is true, then signal its acceptance of the
data by asserting ACK. When ACK becomes true at the target, the
target may change or release DB(7-0, P)* and shall negate REQ. After
REQ is false the initiator shall negate ACK. After ACK is false, the
target may continue the transfer by driving DB(7-0,P)* and asserting
REQ, as described above.
If I/O is false (transfer to the target) the target shall request
information by asserting REQ. The initiator shall drive DB(7-0,P)* to
their desired values, delay at least one deskew delay plus a cable
skew delay and assert ACK. The initiator shall continue to drive the
DB(7-0,P)* until REQ is false.
When ACK becomes true at the target, the target shall read
DB(7-0,P)*, then negate REQ. When REQ becomes false at the initiator,
the initiator may change or release DB(7-0,P)* and shall negate
ACK. The target may continue the transfer by asserting REQ, as
described above.
Synchronous data transfer
-------------------------
Synchronous data transfer may be used only in the data phase if
previously agreed to by the initiator and target through the message
system. The messages determine the use of synchronous mode by both
SCSI devices and establish a REQ/ACK offset and a transfer period.
The REQ/ACK offset specifies the maximum number of REQ pulses that
can be sent by the target in advance of the number of ACK pulses
received from the initiator, establishing a pacing mechanism. If
the number of REQ pulses exceeds the number of ACK pulses by the
REQ/ACK offset, the target shall not assert REQ until the next ACK
pulse is received. A requirement for successful completion of
the data phase is that the number of ACK and REQ pulses be equal.
The target shall assert the REQ signal for a minimum of an assertion
period. The target shall wait at least the greater of a transfer
period from the last transition of REQ to true or a minimum of a
negation period from the last transition of REQ to false before
asserting the REQ signal.
The initiator shall send one pulse on the ACK signal for each REQ
pulse received. The ACK signal may be asserted as soon as the leading
edge of the corresponding REQ pulse has been received. The initiator
shall assert the ACK signal for a minimum of an assertion period. The
initiator shall wait at least the greater of a transfer period from
the last transition of ACK to true or for a minimum of a negation
period from the last transition of ACK to false before asserting the
ACK signal.
Unit attention condition
------------------------
The disc drive sets up the Unit Attention condition when it stores
(within itself) a Unit Attention condition flag for each device on
the SCSI bus having an initiator relationship with the disc drive,
and this Unit Attention condition persists for each initiator until
the condition is cleared (flag negated) by each initiator
individually. The Unit Attention condition results when one of the
following events occur:
1. A power-on sequence occurs.
2. A reset is generated internally by the disc drive (caused by a
power glitch).
3. A Bus Device Reset message causes the disc drive to reset itself.
4. The RESET I/O line resets the disc drive.
5. An initiator changes one or more of the Mode Select parameters in
the disc drive (these changes could affect one or more of the
other initiators).
6. The inquiry data has been changed.
7. The mode parameters in effect for an initiator have been restored
from nonvolatile memory.
8. An event occurs that requires the attention of the initiator.
9. A Clear Queue message received.
10. The Log parameters are changed. Unit Attention Condition is
posted for all initiators in the system other than the one
that changed the Log Parameters.
The Unit Attention Parameters page (page 00h, bit 4 of byte 2) of the
Mode Select Command controls whether or not a Check Condition Status
is to be reported to affected initiators when a Unit Attention
condition exists. The Unit Attention condition for a particular
initiator is cleared when that initiator does one of the following:
1. It sends a Request Sense Command.
2. It sends any other legitimate command, with the exception
of the Inquiry command. The Inquiry command does not clear the
Unit Attention condition.
When a Unit Attention condition flag is stored in the disc drive
for an initiator, the commands that initiator issues to the disc
drive operate as described in the following paragraphs.
If an initiator sends an Inquiry command to the disc drive when the
disc drive has stored a Unit Attention condition flag for that
initiator before or after the disc drive reports Check Condition
status), the disc drive shall perform the Inquiry command and shall
not clear the Unit Attention condition.
If an initiator sends a Request Sense command to the disc drive when
a Unit Attention condition flag is stored for that initiator (before
or after the disc drive reports Check Condition), the disc drive
shall discard any pending sense data, report the Unit Attention Sense
Key, and clear the Unit Attention condition (negate the flag) for
that initiator.
If an initiator issues a command other than Inquiry or Request Sense
while a Unit Attention condition flag is stored for that initiator,
the disc drive may or may not perform the command and report Check
Condition status, depending on whether or not the Unit Attention bit
is zero or one in the Unit Attention Mode Parameters page (Page 00h,
bit 4 of byte 2). If a Request Sense is issued next, the Unit
Attention condition is reported and cleared (flag negated) as noted
in the preceding paragraph. If another command other than Request
Sense or Inquiry is issued instead, the disc drive shall perform the
command and return the appropriate status. The Unit Attention
condition for the subject initiator is cleared (flag negated) and the
sense data and flag indicating there has been a Unit Attention
condition are lost.