N D - 8 7 6 0 S H NEWBURY DATA
NO MORE PRODUCED Native| Translation
------+-----+-----+-----
Form 5.25"/FH Cylinders 1362| | |
Capacity form/unform 675/ 768 MB Heads 15| | |
Seek time / track 15.5/ 2.5 ms Sector/track 54| | |
Controller SCSI1 DIFFERENTIAL Precompensation
Cache/Buffer 45 KB FIFO BUFFER Landing Zone
Data transfer rate MB/S int Bytes/Sector 512
4.800 MB/S ext SYNC
Recording method RLL operating | non-operating
-------------+--------------
Supply voltage 5/12 V Temperature *C 10 50 | -40 60
Power: sleep W Humidity % 8 80 | 8 80
standby W Altitude km -0.305 3.048| -0.305 12.192
idle W Shock g 2 | 20
seek 27.5 W Rotation RPM 3600
read/write W Acoustic dBA
spin-up W ECC Bit 48
MTBF h 40000
Warranty Month
Lift/Lock/Park YES Certificates CSA,FCC,IEC380,IEC950,UL1950
**********************************************************************
L A Y O U T
**********************************************************************
MAXTOR XT-8000S FAMILY QUICK REFERENCE GUIDE 1018333 REV. A
+----------------+---------+------------------------+++---+
| +---J4----+ JP34+JP41|XX
| RN18+ |XX
| || |XX
| +JP37 ++ 1+ |XX
| ++ +JP38 RN19+ |XX
| +JP36 || |XX
| ++ 1+ |XX
| +JP35 +JP40 RN17+ |XX
| ++ ++ |+JP18|X1
| 1++ +-+
| +-+|
+-+ J6-1|
| | +-+|
| J5 J2-1|
+-+ +JP14 +-+
| ++ XX J3
| XX Power
+---------------------------------------------------------+
**********************************************************************
J U M P E R S
**********************************************************************
MAXTOR XT-8000S FAMILY QUICK REFERENCE GUIDE 1018333 REV. A
Jumper setting
==============
x = Jumper set at factory
J2 Auxiliary Connector Pin Assignment
--------------------------------------
+------+------+------+------+------+
|Pin 9 |Pin 7 |Pin 5 |Pin 3 |Pin 1 |
|GND |-WRT |-LED |(key) |+LED |
| |PROTEC| | | |
+------+------+------+------+------+
|Pin 10|Pin 8 |Pin 6 |Pin 4 |Pin 2 |
|ID0 |ID1 |ID2 |GND |(open)|
| | | | | |
+------+------+------+------+------+
When pin seven is connected to ground, the drive is protected from
writing, regardless of commands sent to the drive via the SCSI inter-
face. The write protect signal may also be connected to an LED whose
(+) terminal is tied to a voltage source, so that the LED is
illuminated when the pin is grounded and the drive is in write
protect mode.
For remote write protect, JP18 must be removed.
When an LED is connected to pins one (+) and five (-), that LED
functions in the same manner as the LED which is mounted on the
drive's faceplate. This is typically used in cases when the drive
is positioned where the LED is not visible or the faceplate has been
removed.
Pin three is not present so that users can key the mating connector.
Pin three of the mating connector should be blocked for this purpose.
The SCSI ID of the drive may be programmed remotely by selectively
connecting pins six (ID2), eight (ID1), and ten (ID0) to ground, or
leaving them open.
SCSI ID jumpers (JP35 through JP37) must be removed for the remote
SCSI ID option.
JP37/36/35 SCSI ID
-------------------
+--------+----------+---------+---------+---------+
|SCSI ID | Priority |JP37 ID2 |JP36 ID1 |JP35 ID0 |
+--------+----------+---------+---------+---------+
| 0 | Lowest |OPEN |OPEN |OPEN |
+--------+----------+---------+---------+---------+
| 1 | . |OPEN |OPEN |CLOSED |
+--------+----------+---------+---------+---------+
| 2 | . |OPEN |CLOSED |OPEN |
+--------+----------+---------+---------+---------+
| 3 | . |OPEN |CLOSED |CLOSED |
+--------+----------+---------+---------+---------+
| 4 | . |CLOSED |OPEN |OPEN |
+--------+----------+---------+---------+---------+
| 5 | . |CLOSED |OPEN |CLOSED |
+--------+----------+---------+---------+---------+
|x 6 | . |CLOSED |CLOSED |OPEN |
+--------+----------+---------+---------+---------+
| 7 | Highest |CLOSED |CLOSED |CLOSED |
+--------+----------+---------+---------+---------+
The disk is shipped from the factory with an ID of six. This assures
that sufficient jumpers are available for any address except seven,
which is usually reserved for the host system.
The SCSI device ID can also be set remotely through the auxiliary
connector. The SCSI ID jumpers must be removed for this option. Any
shorting required for a selected ID is done outside the drive.
JP14/JP38 Drive Power-Up Options
---------------------------------
In order to allow for system power supply constraints, which may
require minimizing surge current when powering up multiple drives,
three modes of start up sequencing are provided.
+------+--------------+-----------------------------+
|JP14 |JP38 |Mode |
+------+--------------+-----------------------------+
|OPEN |OPEN |Start by ID Sequence |
+------+--------------+-----------------------------+
|OPEN |CLOSED |Wait for START Command |
+------+--------------+-----------------------------+
x|CLOSED|OPEN or CLOSED|Start when power is Applied |
+------+--------------+-----------------------------+
Start by ID Sequence
With both JP14 and JP38 out, the drive delays spinup for approxi-
mately 11 to 13 seconds times the SCSI ID. This allows for power up
sequencing. A RESET condition results in the drive delaying its
spinup according to its SCSI ID.
Wait for Start Command
With JP14 out and JP38 in, the drive does not spin up until the
initiator issues a START/STOP UNIT Command with the start bit equal
one.
Start when power is Applied
When JP14 is in and JP38 is out, the motor starts as soon as power is
applied. The drive is shipped in this configuration.
JP41/34 Terminator Power Selection
-----------------------------------
Power to the terminators may come internally from the drive, or
externally from the SCSI bus.
JP34 OPEN
x JP41 CLOSED Terminator power is internal, from the drive
JP41 OPEN
JP34 CLOSED Terminator power is external, from the SCSI bus
With both JP41 and JP34 in, terminator power is provided from the
drive and to the SCSI bus. Hence, the drive is at one end of the SCSI
bus with terminators in place and is also supplying terminator power
for the device at the other end of the SCSI bus.
JP18 Write Protect Option
--------------------------
JP18 CLOSED Data cannot be written to the drive; only READ opera-
tion can be executed.
Installation of JP18 grounds the remote write protect line, J2, pin
seven, forcing WRITE PROTECT on, and prevents remote control through
J2-7 on the ten-pin connector.
As shipped from the factory, JP18 is out, allowing normal reading/
writing, or optional remote control through the J2 connector.
JP40 Parity Option
-------------------
x JP40 CLOSED Enables odd parity detection in the drive.
OPEN Disables odd parity detection in the drive.
Odd parity is always generated by the drive and provided to the SCSI
bus.
Other Jumpers
-------------
Other jumper positions not shown are not user selectable. These
jumpers are for factory use only. Improper operation may occur if
non-user jumpers are changed.
J3 DC Power and pin connector assignments
-------------------------------------------
+------------+ pin 1 +12 VDC
| 4 3 2 1 | pin 2 +12 Volts Return
+------------+ pin 3 + 5 Volts Return
pin 4 + 5 VDC
**********************************************************************
I N S T A L L
**********************************************************************
MAXTOR XT-8000S FAMILY QUICK REFERENCE GUIDE 1018333 REV. A
Notes on Installation
=====================
Installation direction
----------------------
horizontally vertically
+-----------------+ +--+ +--+
| | | +-----+ +-----+ |
| | | | | | | |
+-+-----------------+-+ | | | | | |
+---------------------+ | | | | | |
| | | | | |
| | | | | |
+---------------------+ | +-----+ +-----+ |
+-+-----------------+-+ +--+ +--+
| |
| |
+-----------------+
The drive will operate in all axis (6 directions).
Mounting
--------
The drive may be mounted in any orientation. In any final mounting
configuration, ensure that the operation of the three shock mounts
which, isolate the base casting from the frame is not restricted.
Certain switching power suppplies may emanate electrical noise, which
can degrade the specified read error rate. For best results, orient
the drive so that the PCB assembly is not adjacent to these noise
sources.
Mounting Holes
--------------
Eight mounting holes, four on the bottom and two on each side, are
provided for mounting the drive into an enclosure. The size and
location of these holes are identical to industry standard floppy
drives.
Caution: The casting is very close to the frame mounting holes in
some locations. Mounting screws lengths must be chosen such that no
more than 0.125 inch of the screw is available to enter the frame
mounting hole. The torque applied to the mounting screws must be
between 9 and 12 inch pounds.
J1/P1 SCSI Connector
--------------------
Connection to J1 is via a non-shielded fifty-conductor connector P1,
consisting of two rows of twenty-five female contacts on 0.1 inch
centers. Recommended strain-relief connectors are AMP part-number
1-499506-2, or Dupont part number 669002 (66900-250). Use of a keyed
connector is strongly recommended.
J2/P2 Auxiliary Connector
-------------------------
Connector J2 is an auxiliary connector providing remote control of
write protect and SCSI ID, and the ability to carry the LED signal
beyond the drive. The auxiliary connector is a Berg 68451-121,
ten-pin part. The mating connector is a 3M 3473-6010 part.
J3/P3 Power Connector
---------------------
The DC power connector, J3, is a four-pin AMP MATE-N-LOCK connector,
part number 350543-1. The recommended mating connector is part
number 1-480424-0. using AMP pins part number 350078-4 (strip) or
part number 61173-4 (loose piece).
J4/P4 Ground
------------
The DC ground connector is a Faston-type connector, AMP part number
61761-2. The recommended mating connector is AMP part number 62187-1.
If wire is used, the hole in J4 will accommodate a maximum wire size
of 18 AWG. This wire should be grounded to the AC ground or to the
metal of the computer frame.
Sector Size
-----------
The drive is shipped from the factory formatted with 512 byte
sectors. Configuration parameters are default values in all optional
cases. It is recommended that users reformat the drive with the
user's sector size, using the Plist and the user's configuration
parameters.
Interface Termination
---------------------
SCSI devices require proper interface termination. The first device
and the last device on the daisy chain SCSI bus must be terminated.
Remove the terminators from any devices in between. For instance, if
the drive is in the middle of the string, remove its terminators.
Pin one is on the end of the terminator that is marked with a dot.
Note that the hole/solder pad for pin one has a square outline,
whereas all others have a round outline. Pin one is oriented toward
the power connector, J3.
Note: All terminator packs (RN17 through RN19) must be oriented
with the dot toward J3 for the drive to work properly.
As shipped, interface signal lines are terminated with three
removable 220/330 ohm resistor network packs.
The device driving the drive inputs should be open collector devices
capable of sinking at least 48 milliamps at a voltage level of less
than 0.5 volts DC (7438 or equivalent).
Devices receiving the drive inputs should be SCHMITT trigger type
to improve noise immunity; 74LS14, 74LS240, or equivalent. The
initiator should not load bus with more than one standard low power
Schottky transistor-transistor logic (LSTTL) input load per line. The
initiator should terminate all signals with 220/330 ohm terminators.
Removable Faceplate
-------------------
The faceplate may be removed in installations where it is not
required. Remove the two C-clips and unplug the LED cable from the
PCB.
**********************************************************************
F E A T U R E S
**********************************************************************
MAXTOR XT-8000S FAMILY QUICK REFERENCE GUIDE 1018333 REV. A
Seek Time
---------
| 8380S | 8760S |
----------------------------------+--------+--------+
Track-to-Track msec. typ. | 2.5 | 2.5 |
msec. max. | 3 | 3 |
Average msec. typ. | 14.5 | 16.5 |
Average msec. max. | 16 | 18 |
Full Stroke msec. typ. | 29 | 30 |
msec. max. | 35 | 35 |
----------------------------------+--------+--------+
Seek Time includes Settling Time.
Reliability Specifications
--------------------------
MTBF 40,000 POH, Typical Usage
PM Not Required
MTTR 30 Minutes
Component Design Life 5 Years
WARRANTY
--------
Maxtor warrants the XT-8000S Family disk drives against defects in
materials and workmanship for a period of twelve months, for the
original purchaser. Direct any questions regarding the warranty to
your Maxtor Sales Representative. Maxtor maintains Customer Service
Centers for the repair and reconditioning of all Maxtor products.
Direct all requests for repair to the Maxtor Service Center in San
Jose. This assures you of the fastest possible service.
REGULATORY APPROVALS
--------------------
UL Recognition obtained: File Number E87276 (S)
CSA Certification obtained: File Number LR54048-6
VDE Recognition obtained: File Number 37230G
Technical Data Restrictions
---------------------------
In case of sale to or use of units by DoD, use, duplication or
disclosure of any software, firmware or related documentation is
subject to restrictions stated in paragraph (c) (1) (ii) of the
Rights in Technical Data and Computer Software clause at DFAR
252.227-7013. For Civilian Agencies: Use, reproduction, or disclosure
of the software and related documentation is subject to restrictions
set forth in FAR 52.227-19. Unpublished rights reserved under the
copyright laws of the United States. Maxtor Corporation, 211 River
Oaks Parkway, San Jose, CA 95134.
Product Description
-------------------
The XT-8000S Family disk drives are low cost, high capacity, high
performance, random access storage devices which use nonremovable
5.25 inch disks as storage media. Each disk surface employs one
moveable head to access the data tracks. The total unformatted
capacity of these disk drives ranges from 410 to 769 megabytes.
The disk drive includes the Small Computer System Interface (SCSI)
controller embedded in the disk drive electronics. Some of the
resulting benefits of having an integrated controller include the
elimination of a separate controller printed circuit board (PCB),
reduction in the number of associated cables, and elimination of the
controller-specific power supply.
Low cost and high performance are achieved through the use of a
rotary voice coil actuator and a closed loop servo system using a
dedicated servo surface. The innovative MAXTOR rotary voice coil
actuator provides performance usually achieved only with larger,
higher powered linear actuators. The closed loop servo system
and dedicated servo surface combine to allow state of the art
recording densities (1,376 tracks per inch, and 31,596 bits per inch)
in a 5.25 inch package.
High capacity is achieved by a balanced combination of high areal
recording density, run-length limited (RLL) data encoding, and high
density packaging techniques. Maxtor's advanced MAXPAK electronic
packaging technique uses miniature surface mounted devices to
allow all electronic circuitry to fit on one PCB. Advanced flexures
and heads allow closer spacing of the disks; therefore, a greater
number of disks fit in a 5.25 inch package. Maxtor's unique
integrated disk drive motor/spindle design allows a deeper head/disk
assembly (HDA) casting than conventional designs, thus permitting
eight disks to be used.
The disk drive's electrical interface is compatible with the American
National Standards Institute (ANSI) SCSI standard X3.131-1986, plus
the Common Command Set (CCS) requirements. Size and mounting conform
to the industry standard 5.25 inch form factor for floppy and
Winchester disk drives, and the same direct current (DC) voltages and
connectors are used.
SUMMARY OF SUPPORTED SCSI COMMANDS
For more information on Group 0 and Group 1 commands for
direct-access devices, see the reference documents below:
- ANSI X3.131-1986, Small Computer System Interface (SCSI), American
National Standards Institute, Inc., June 23, 1986.
- X3T9.2/85-52 Rev 4.B Common Command Set (CCS), a document of the
American Standards Committee.
GENERAL THEORY OF OPERATION
---------------------------
The disk drive consists of read/write, control, and interface
electronics, read/write heads, a servo head, a head positioning
actuator, a disk drive motor/spindle, the disk media, and an air
filtration system. The components perform the following functions:
- interpret and generate control signals
- position the heads over the desired track
- read and write data
- provide automatic error correction to the data
- provide a contamination-free environment
- provide a controller to interact with the initiator
- maintain precise spindle rotation speed
READ/WRITE CONTROL AND SCSI CONTROLLER ELECTRONICS
--------------------------------------------------
All the disk drive and controller electronics are packaged on a
single PCB. This PCB, which includes three microprocessors, performs
the following disk drive functions:
- data separation
- reading and writing of data
- index detection
- head positioning
- head selection
- disk drive selection
- fault detection
- track zero detection
- recalibration to track zero on power up
- track position counter
- power and speed control for the spindle disk drive motor
- braking for the spindle disk drive motor
- disk drive up-to-speed indication
- reduced write current on the inner tracks
- monitoring for WRITE FAULT conditions
- control of all internal timing
- generation of SEEK COMPLETE signals
- RLL encoding/decoding
The PCB also performs the following controller functions:
- error detection and correction
- SCSI bus disconnect/reconnect functions
- SCSI bus arbitration
- defect handling
- data transfer
- automatic retries
- data buffering
- command linking
- sector formatting
DISK DRIVE MECHANISM
--------------------
The HDA is a sealed subassembly containing the mechanical portion of
the disk drive. A brushless DC drive motor contained within the
spindle hub rotates the spindle and is controlled by a dedicated
microprocessor. The motor and spindle are dynamically balanced to
insure a low vibration level, and dynamic braking is used to quickly
stop the spindle motor when power is removed. The HDA is shock
mounted to minimize transmission of vibration through the frame. The
frame is the mechanical assembly holding the HDA and PCB.
AIR FILTRATION SYSTEM
---------------------
The disks and read/write heads are assembled in a Class 100
environment and then sealed within the HDA. The HDA contains an
absolute filter mounted inside the casting to provide constant
internal air filtration. A second absolute filter, located on the HDA
top cover, permits pressure equalization between the internal and
ambient air.
HEAD POSITIONING MECHANISM
--------------------------
The read/write heads are mounted on a head/arm assembly which is then
mounted on a ball bearing supported shaft. The voice coil, an
integral part of the head/arm assembly, lies inside the magnet
housing when installed in the disk drive. Current from the power
amplifier, which is controlled by the servo system, induces a
magnetic field in the voice coil. This electrically induced field
either aids or opposes the existing fields of the permanent
magnets. The interaction of the permanent and induced magnetic fields
causes the voice coil to move. Since the head/arm assemblies are
mounted on the voice coil, the voice coil movement is translated
through the shaft pivot point directly to the heads. The movement of
the head/arm assembly in conjunction with the information from the
servo system positions the heads over the correct cylinder.
Movement of the voice coil actuator is controlled by the servo
feedback signal from the servo head. The servo information is written
onto the disk at the factory and provides the following control
signals for the actuator:
track-crossing signals during a seek operation, track-following
signals during on cylinder operation, and timing information such as
index and servo clock. Servo information also provides the timing
necessary to divide a track into the sectors used for data storage.
The servo control system has a dedicated microprocessor for fast,
optimized performance.
READ/WRITE HEADS AND DISKS
--------------------------
The disk drive employs state of the art sliders and flexures. The
configuration of the sliders and flexures provides improved
aerodynamic stability, superior head/disk compliance and an extremely
high signal-to-noise ratio.
The disk media is a thin, nickel-cobalt, metallic film deposited on
130 millimeter diameter aluminum substrates. The coating formulation
together with the low load force/low mass heads permits highly
reliable contact start/stop operation. The nickel-cobalt metallic
film yields high amplitude signals, and very high resolution
performance compared to conventional oxide coated media.
The metallic media also provides a highly abrasion and impact
resistant surface, decreasing the potential for damage caused by
shipping shock and vibration.
Data on each of the data surfaces is read by one read/write head, and
each head can access 1,632 physical tracks. There is one surface
dedicated to servo information in each disk drive.
TRACK AND SECTOR FORMAT
-----------------------
The standard track format is organized into sectors
The sectors are addressed via the logical block address (LBA) in the
SCSI commands. The method of encoding used is 2, 7 RLL.
Initiator-Target Configurations
-------------------------------
The SCSI initiator interface offers a number of unique advantages
which facilitate the interconnection of the disk drive with one (or
more) computer systems. Unlike traditional microcomputer disk
interfaces, such as ST506, SCSI supports multiple peripherals and
different peripheral types all operating on the same bus structure.
The disk drive also supports multiple host configurations consistent
with the established arbitration cycle outlined in the SCSI
standards. Configuration changes are made by changing the SCSI
address jumpers. These jumpers should be set and verified when the
disk drive is installed in the system.
The SCSI implementation used on the disk drive is intended to
facilitate high-speed data transfer between the initiator and the
disk drive. Interconnection between the initiator(s) and the disk
drive is via a fifty-conductor ribbon cable and uses the single-ended
alternative (the single-ended alternative allows up to 6 meters of
cable length).
Logical/Electrical Signal Definitions
The SCSI bus uses +5 volts (termination power), ground, and eighteen
signal lines. Nine signals are for the 8-bit data bus with one data
parity bit; the other nine signals are the SCSI control lines which
coordinate access to the bus for transfers of commands, data, status,
and messages. The interface signals are listed below; please refer to
the published SCSI standard for further details.
Across the SCSI bus all initiator signals are low-true for the single
ended version. The signals are asserted, or active, at 0 to 0.5 volts
DC, and deasserted, or inactive, at 2.5 to 5.25 volts DC. This
low-true logic is indicated by the negative sign which precedes the
signal name.
-RST
The -RST (reset) signal is an OR-tied signal asserted by the
initiator, causing the drive to do a "hard" RESET, self configure and
return to the IDLE condition. This signal is normally used during a
power-up sequence. The - RST pulse should be at least 25 microseconds
wide.
-SEL
The -SEL (select) signal, accompanied by the disk drive's SCSI ID bit
(zero through seven), is asserted by the initiator and causes the
disk drive to be selected. The - SEL line must be negated by the
initiator after the disk drive asserts the -BSY line in response to a
proper selection. The signal can be asserted by the arbiter
(initiator or drive) in the ARBITRATION phase. The signal is also
asserted by the disk drive during the RESELECTION phase.
-BSY
The -BSY (busy) signal is an OR-tied signal asserted by the drive,
indicating that the bus is being used. It is also asserted by the
arbiter during the ARBITRATION phase and by the initiator and the
disk drive during the RESELECTION phase.
-C/D
Assertion of the -C/D (control/data) signal by the disk drive
indicates that command, status, or message information is to be
transferred on the data bus. Negation of this line indicates that
data is to be transferred on the data bus.
-I/O
When the -I/O (input/output) signal is asserted by the disk drive it
indicates that information is transferred to the initiator from the
disk drive. Negation of the signal indicates that information is
transferred to the disk drive from the initiator. Note that IN means
toward the initiator.
-REQ
When asserted by the disk drive, the -REQ (request) signal indicates
that a byte is to be transferred on the data bus. -REQ is negated
following assertion of the -ACK line by the initiator.
-ACK
The -ACK (acknowledge) signal is asserted by the initiator, following
the assertion of the -REQ line, to indicate that data has been
accepted by the initiator, or that data is ready to be transferred
from the initiator to the disk drive. -ACK is negated following
negation of the -REQ line.
-ATN
The -ATN (attention) signal is asserted by the initiator to indicate
the ATTENTION condition, which is a request by the initiator for the
disk drive to enter the MESSAGE OUT phase.
-MSG
The -MSG (message) signal is asserted by the disk drive during one of
the message phases. Messages may be either IN or OUT, depending on
the state of the -I/O signal.
-DB (7-0, P)
The eight bidirectional data bus lines (DB 7-0) and the parity line
(DBP) are used to transfer 8-bit parallel data to or from the
initiator. Bit seven is the most significant bit. Bits zero through
seven are also used as SCSI ID bits during the ARBITRATION, SELECTION
and RESELECTION phases. Data bus parity (DBP) is odd.
ELECTRICAL POWER INTERFACE
--------------------------
This subsection describes the power-up sequence for the disk drive,
and the two connectors associated with the electrical power
interface. These connectors are the power connector, J3, and the
frame ground connector, J4.
Power-Up Sequence
-----------------
DC power (+5 volts and +12 volts) may be supplied in any order. Both
power supplies must be present, and within the tolerances of the
power sensing circuit, before the motor will spin up. When the
spindle reaches full speed, the actuator lock automatically
disengages. The disk drive performs automatic seek calibration during
start up for optimum seek performance. The disk drive spins up and
becomes ready in 20 to 30 seconds. The disk drive executes its
recalibration sequence whenever power is applied or the START STOP
UNIT command is received. You may delay starting the spindle motor,
to minimize power surges in multidrive configurations, by using the
jumper options.
SHIPPING
--------
At power down, the heads are automatically positioned over the
nondata, dedicated landing zone on each disk surface. The automatic
shipping lock solenoid is also engaged at this time. Maxtor ships the
disk drive in single- and multipack shipping containers. Users can
ship the disk drive installed when the nonoperating shock and
vibration limits are not exceeded.
DRIVE POWER-UP OPTIONS
----------------------
In order to allow for system power supply constraints, which may
require minimizing surge current when powering up multiple disk
drives, three modes of start-up sequencing are provided.
Start by ID Sequence: Both JP14 and JP38 are out. The disk drive
delays spinup for approximately 11 to 13 seconds multiplied by the
SCSI ID. This allows for power-up sequencing. A RESET condition
results in the disk drive delaying its spinup according to its SCSI
ID.
Wait for START Command: JP14 is out and JP38 is in. The disk drive
does not spinup until the initiator issues a START STOP UNIT command
with the start bit equal to one.
Start When Power Is Applied: JP14 is in and JP38 is out. The motor
starts as soon as power is applied. The disk drive is shipped in this
configuration.
TERMINATOR POWER SELECTION
--------------------------
Single Ended Version: Power to the terminators may come internally
from the disk drive, or externally from the SCSI bus. If JP41 is in,
the terminator power is provided by the disk drive. If JP34 is in,
the terminator power is external, from the SCSI bus.
If both JP41 and JP34 are in, terminator power is provided from the
disk drive and to the SCSI bus. Hence, the disk drive is at one end
of the SCSI bus with terminators in place and is also supplying
terminator power for the device at the other end of the SCSI bus.
Differential Version: The differential version does not provide for
termination on the PCB. Therefore, JP34 is shipped installed and JP41
is not supported. This will provide +5v to the SCSI bus for external
termination.
INTERFACE TERMINATION
---------------------
SCSI devices require proper interface termination. The first device
and the last device on a SCSI bus daisy chain must be terminated.
Remove the terminators from any devices in between. For instance, if
a disk drive is in the middle of a SCSI bus daisy chain, remove its
terminators.
Terminator pin one is marked with a dot on the terminator.
The orientation of the terminator on the PCB is also shown. Note that
the PCB's hole/solder pad for pin one has a square outline,
whereas all the other holes/pads have a round outline. Also, note
that pin one is always the closest pin to the power connector, J3.
NOTE: All terminator packs (RN17 through RN19) must be oriented with
the dot towards J3 for the disk drive to work properly.
As shipped, the interface signal lines are terminated with three
removable 220/330 ohm resistor network packs.
The devices driving the disk drive inputs should be open collector
devices capable of sinking at least 48 milliamps at a voltage level
of less than 0.5 volts DC (7438 or equivalent).
Devices receiving the disk drive outputs should be of SCHMITT trigger
type to improve noise immunity (74LS14, 74LS240, or equivalent). The
initiator should not load the bus with more than one standard low
power Schotky transistor-transistor logic (LSTTL) input load per
line, and should terminate all signals with 220/330 ohm terminators.
NOTE: The differential version does not provide for termination on
the PCB. External terminators are available from Maxtor.
POWER UP AND BUS RESET
----------------------
The following sections describe the sequence of events during drive
self-test and initialization sequences. The self-test sequence occurs
before the initialization sequence.
Self-Test Sequence
------------------
The self-test sequence is executed upon drive power up. The self-test
sequence verifies the integrity of the hardware. This test is not an
exhaustive hardware diagnostic, but checks the major components for
full function. The drive does not respond to SELECTION for the
first 250 milliseconds of the self-test. After 250 milliseconds have
elapsed, the drive responds to SELECTION with a BUSY status for 2 to
3 seconds: this time is spent completing the remaining self-test
sequences, initializing the SCSI circuitry, and enabling the SCSI
interrupts. After the self-test is complete and the interface
circuitry is initialized (approximately 3 seconds), the drive
responds to SELECTION with CHECK CONDITION status and the appropriate
sense data (i.e., UNIT ATTENTION, POWER ON/RESET condition).
The self-test sequence consists of the following events:
- Hardware Reset Test - This routine tests the microprocessor, buffer
controller, disk formatter, and SCSI reset latch for the proper
power up condition. If any of these tests fail, the drive can only
be reset by a POWER UP condition.
- Microprocessor Test - This routine tests the microprocessor's
internal memory, timers, and register bank switching for proper
operation.
- Erasable Programmable Read Only Memory (EPROM) Checksum Test - This
routine performs a checksum calculation on the controller firmware
EPROM and compares it against the checksum stored in the EPROM.
- Buffer Controller Test - This routine tests the buffer controller
for proper operation. All the registers are tested and the chip is
engaged to access random-access memory (RAM).
- Dynamic RAM Test - This routine tests the dynamic RAM by writing
and reading different patterns to memory. In addition, the buffer
controller is tested for proper refresh operation and parity
detection. This test also tests the memory parity interrupt.
- Disk Formatter Test - This routine tests the disk formatter chip by
writing and reading all possible patterns to each of the disk
formatter chip registers. After the registers are tested, the
interrupts are tested to ensure that the formatter chip generates
an interrupt when a command completes.
- SCSI Controller Test - This routine tests the SCSI controller chip
by executing the chip diagnostic command. After the diagnostic test
completes, the interrupts are tested to ensure that the SCSI chip
generates an interrupt when a command completes. Finally, the
registers are tested by writing and reading all possible patterns
to each of the SCSI controller chip registers.
If any portion of the self-test fails, except the hardware reset
test, the drive can be reset by a SCSI bus RESET condition or a power
up RESET condition. The failure of the hardware reset test is
considered a catastrophic failure and the controller can only be
reset from such a failure by a power up RESET condition.
