M 8 4 5 0 MINISCRIBE
NO MORE PRODUCED Native| Translation
------+-----+-----+-----
Form 3.5"/HH Cylinders 771| | |
Capacity form/unform 41/ 48 MB Heads 4| | |
Seek time / track 45.0/12.0 ms Sector/track 26| | |
Controller RLL / ST506 Precompensation 128
Cache/Buffer KB Landing Zone
Data transfer rate 0.938 MB/S int Bytes/Sector 512
0.938 MB/S ext
Recording method RLL 2/7 operating | non-operating
-------------+--------------
Supply voltage 5/12 V Temperature *C 4 50 | -40 60
Power: sleep W Humidity % 8 80 | 5 95
standby W Altitude km -0.061 3.048| 12.192
idle 10.7 W Shock g 10 | 70
seek W Rotation RPM 3600
read/write W Acoustic dBA 45
spin-up W ECC Bit
MTBF h 20000
Warranty Month
Lift/Lock/Park YES Certificates FCC
**********************************************************************
L A Y O U T
**********************************************************************
MINISC. 8450 PRODUCT MANUAL P/N 1105 REV. B, SEPTEMBER 1988
+---------------------------------------------------------+
| |XX
| +-SEL1 |XX
| | | |XX P2
| | | |XX
| +J15+-+ |XX
| ++ |
| +J13 |XX
++ LED ++ |XX
++ ++ |XX P1
| RP1|| |XX
| Terminator|| |XX
| || |XX
| ++ ++ |XX
| |J12 |XX
| ++ |XX
| |
+--------------------------------------------------xxxxxx-+
Power xxxxxx
**********************************************************************
J U M P E R S
**********************************************************************
MINISC. 8450 PRODUCT MANUAL P/N 1105 REV. B, SEPTEMBER 1988
Jumper Setting
==============
Drive Select
------------
As shipped, the drive is preselected for drive select address 1. To
change to another address, the two position jumper located in row of
the SEL 1 header must be repositioned to one of the other three rows
corresponding to the desired drive select number. Row 1, correspond-
ing with Drive Select 1, is the topmost row when the interconnected
column of pins is on the right.
SEL 1
+---+ +---+ +---+ +---+
1 |xxx| 1|O O| 1|O O| 1|O O|
2 |O O| 2|xxx| 2|O O| 2|O O|
3 |O O| 3|O O| 3|xxx| 3|O O|
4 |O O| 4|O O| 4|O O| 4|xxx|
+---+ +---+ +---+ +---+
Drive 1 Drive 2 Drive 3 Drive 4
As shipped by MiniScribe with Drive Select 1 selected.
Drive Exercise/Head Park Option
-------------------------------
When power is first applied, the drive performs power-on diagnostics.
After the diagnostics, the status of jumper 13 is checked. It is
open, the normal drive ready mode is entered. If jumper 13 is
closed (jumpered), the drive enters the exercise mode where crescendo
seeks are performed continually until power is removed. Any seek or
spin failure occurring during this mode causes the drive diagnostic
LED to flash a code indicating the type of failure.
To park the heads, remove power and place a jumper in J13. Apply
power. The heads will rezero (go to cylinder 0) and then to the
shipping zone at cylinder 810 when power is removed. Remove the
jumper immediately.
Low Power/Head Park Option
--------------------------
The jumper in J15 removed enables the low power option. With this
option, whenever the drive has not been selected for 30 seconds the
head assembly is automatically moved to the shipping cylinder (810)
and current is removed from the stepper motor. In this mode the drive
power consumption is reduced to 7 watts. Should power be removed
from the drive at this point, the heads will land in the shipping
zone. If power is not removed, the heads will remain over the
shipping cylinder until told to go to the cylinder indicated by the
next Read or Write command.
Terminators
-----------
Each drive is shipped with a terminator pack providing the 220/330
ohm termination for the Control Input Signals. If multiple drives are
configured in a daisy chain configuration, the terminator pack must
be removed from all drives except the last unit on the daisy chain.
Diagnostic and Exercise Routines
--------------------------------
The microprocessor performs wake up diagnostics upon application of
power. If an error is detected, the processor will flash a warning by
blinking the activity LED. Some errors are fatal in that they do not
return to the program until power is cycled.
If no errors are detected, the processor tests Jumper 13 to determine
its state (open or closed). Briefly, Jumper 13 (Drive Exercise
Options) is as follows:
The jumper is left open for normal (online) operations. If the
jumper is closed, (and left closed) a burn-in (cresendo seeks)
program will be run. If the jumper is closed and opened during the
code level display, the sensor adjust routine is initiated.
Power-up sequence of events is as follows:
1. Apply power
2. The microprocessor runs power on diagnostics and then allows motor
spin up.
3. Test Jumper 13. If open, go to normal operation. If closed,
continue to Step 4.
4. Display code level (5 bits), e.g. 00001
5. Test Jumper 13. If still closed, continue in cresendo seek
exerciser mode. If open, run Track Zero sensor adjust.
6. Recalibrate access, then seek to maximum cylinder.
7. The LED will display seven zero's (flash code). At this time the
heads are located over the shipping zone. If power is removed, the
heads will land in the shipping zone.
8. If the test is continued the drive will perform a seek to
cylinder four, (test for seek error) and then seek to cylinder
zero.
9. At this point the sequential seek burn-in will begin.
**********************************************************************
I N S T A L L
**********************************************************************
MINISC. 8450 PRODUCT MANUAL P/N 1105 REV. B, SEPTEMBER 1988
Notes on Installation
=====================
Recommended Mounting Configuration
----------------------------------
The MiniScribe 8450 3 1/2 inch size drive is designed to be used in
applications where the unit may experience shock and vibrations at
greater levels than larger and heavier disk drives.
Two features which allow greater shock tolerances are the use of
rugged media and shock mounts. To take full advantage of the shock
mounts, however, it is necessary to provide a 0.1 inch clearance on
both the top and bottom of the drive. This clearance allows for move-
ment of the drive during acceleration.
The drive may be mounted in any attitude.
The drive is mounted using 6-32 screws, 1/8 inch maximum penetration.
The customer should allow adequate ventilation for the drive to
ensure reliable drive operation over the operating temperature range.
Mechanically Isolated Mounting Points
-------------------------------------
Four side mounting and four base mounting points are provided to the
customer. Each mounting point is mechanically isolated from the head-
disk assembly.
Cabling
-------
Connect interface cables with connectors P1, P2, and P3 to J1,
J2, and J3 respetively. Insure that connectors P1 and P2 have
keys installed. If multiple drives are be interconnected, remove the
terminator packs in all but the last drive in the daisy chain.
Magnetic Field
--------------
The externally induced magnetic flux density may not exceed 3 Gauss
as measured at the disk surface.
Drive Mechanism
---------------
A brushless DC direct drive motor rotates the spindle at 3600 rpm.
The motor/spindle assembly is dynamically balanced to provide minimal
mechanical runout to the disks. A dynamic brake is used to provide a
fast stop to the spindle motor when power is removed.
Air Filtration System
---------------------
Within the sealed enclosure, a 0.3 micron filter coupled with a
breather filter provides over the drive life a clean, above
atmospheric pressure environment to the heads and disks.
Head Positioning Mechanism
--------------------------
Four read/write heads on the drive are supported by a carriage
mechaism coupled to the stepper motor through a rack-and-pinion
motion translator.
Read/Write Heads and Disks
--------------------------
Data is recorded on two (2) 95 mm diameter disk through four (4)
Mini-Winchester type composite heads.
Power Sequencing
----------------
+5 volts DC and +12 volts DC may be applied in any order.
+12 VDC powers the spindle drive motor. The microprocessor verifies
that the disks are spinning at 3600 rpm and then activates the
automatic Track Zero positioning. -TRACK ZERO, -SEEK COMPLETE, and
-READY will beome true upon completion of the Track Zero positioning
sequence.
Electrical Interface
--------------------
The interface to the MiniScribe 8450 can be divided into three
categories, each of which are physically separated: Comtrol Signals,
Data Signals and DC Power.
All Control Signals are digital in nature (open collector TTL) and
either provide signals to the drive (input) or signals to the
controller (output). The Data Signals are differential in nature and
provide data either to (write) or from (read) the drive.
The interconnect cable between the drive and controller may be flat
ribbon or twisted pairs of a length not to exceed 20 feet. The signal
return lines and ground lines for P1 and P2 should be grounded at the
controller.
The voltage return lines of P3 should only be grounded at the power
supply.
Cable Interconnection - 4 Drive System
--------------------------------------
HOST
+-----------+ +-----------------+
| +---o---Control------------------+P1 Drive 1 |
| | | +-------Data------------+P2 |
| | | | +-Power---+P3 ... |
| | | | | +-----------------+
| | | | | +-----------------+
|Controller | o----+-------------+---------+P1 Drive 2 |
| | | | +-----------+---------+P2 |
| | | | | o---------+P3 ... |
| | | | | | +-----------------+
| | | | | | +-----------------+
+-----------+ o----+-+-----------+---------+P1 Drive 3 |
| | | | | +---------+---------+P2 |
| +---+----+ | | o---------+P3 ... |
| +---+------+ | | +-----------------+
|Data +---+--------+ | +-----------------+
|Separator | +------------------+---------+P1 Drive 4 |
| +----------------------+---------+P2 |
| | o---------+P3 XXX |
+-----------+ | +-----------------+
DC voltages----+
... = Terminator Pack removed
XXX = Terminator Pack installed
P1 Connector - Control Signals
------------------------------
Connection to P1 is through a 34 pin PCB edge connector. The pins are
numbered 1 through 34 with the odd pins located on the componet side
of the printed circuit board. A key slot is provided betweeen pins 4
and 6.
The recommended mating connector (J1) is AMP Ribbon Connector, P/N
88373-3.
P2 Connector - Data Signals
---------------------------
Connection to P2 is through a 20 pin edge connector. The pins are
numbered 1 through 20 with the odd pins located on the component side
of the Printed Circuit Board. A key slot is provided between pins 4
and 6.
The recommended mating connector (J2) is AMP Ribbon Connector, P/N
88373-6.
P3 Connector - DC Power
-----------------------
DC power connector (P3) is a 4 pin AMP Mate-N-Lok connector, mounted
on the PCB.
The recommended mating connector (J3) is AMP P/N 1-480424-0 utilizing
AMP pins P/N 350078-4.
+-----P3-----+ pin 1 +12 VDC
| 4 3 2 1 | pin 2 +12 Ground Return
+------------+ pin 3 + 5 Ground Return
pin 4 + 5 VDC
Caution/Warning
---------------
The Miniscribe drive is a precision product weighing 1.8 pounds.
During handling the unit must not be dropped, jarred or bumped.
Otherwise, damage to the heads and disks may occur. When the drive is
removed from the Miniscribe shipping container and not immediately
secured within a chassis through its shock mounts, it must be stored
on a soft padded surface.
Failure to comply with the above procedure will render null and void
all warranties.
When removing the PCBA, a grounded wirst strap must be worn to
prevent esd damage.
**********************************************************************
F E A T U R E S
**********************************************************************
MINISC. 8450 PRODUCT MANUAL P/N 1105 REV. B, SEPTEMBER 1988
Introduction
------------
The MiniScribe 8450 is a half-height reandom access 95 mm rigid
media disk drive employing Winchester technology. The drive utilizes
a rack-and-pinion actuator, microprocessor control, and open loop
stepper head positioning.
The Model 8450 features power up diagnostics, buffered seek and 7.5
Megabit/Sec. transfer rate. D.C. voltages and physical form factor
are the same as the 3-1/2 inch half height floppy disk drive.
Seek Time (including settling time)
-----------------------------------
+----------------------------------+--------+
| | 8450 |
+----------------------------------+--------+
|Track-to-Track msec. typ. | 12 |
+----------------------------------+--------+
|Average msec. typ. | 45 |
| msec. max. | 96 |
+----------------------------------+--------+
|Latency msec. avg. | 8.33 |
+----------------------------------+--------+
Media Defect Criteria (as shipped from MiniScribe)
--------------------------------------------------
Model 8450 10 defects surface/maximum
20 defects maximum
2 bytes or less in length
Cylinder Zero and One Defect Free
Error Messages
--------------
The microprocessor performs wake up diagnostics on power up.
Additionally, some operations are monitored during normal operations.
If an error is detected, the microprocessor will flash a warning by
blinking the activity LED.
Error codes may be generated by the microprocessor to indicate hard-
ware failures or warnings that are detected during power-on
diagnostics, burn-in mode, or normal operation. Error codes are
diaplayed in a "morse-code" type manner. Bits may be interpreted and
converted into hexadecimal error codes. "Zeros" are indicated by
a short (1/2 second) flashingn mode. "Ones" are indicated by a short
(1/2 second) continuous ON mode. Error "Words" are separated by a one
second LED off time.
Zero = 0.5 second flashing mode
One = 0.5 second continuous ON mode
Between Bits = 0.5 second Off
Between Repeat Cycles = 1.0 second Off
Listed Below are the binary to hexadecimal conversion values:
0 = 0000 4 = 0100 8 = 1000 C = 1100
1 = 0001 5 = 0101 9 = 1001 D = 1101
2 = 0010 6 = 0110 A = 1010 E = 1110
3 = 0011 7 = 0111 B = 1011 F = 1111
Message Definitions
-------------------
Code 0 - Microprocessor RAM error
Code 1 - Microprocessor ROM checksum error
Code 2 - Interface chip diagnostic failure
Code 3 - Write Fault latch will not reset
Code 4 - Index pulse not detected during spinup
Code 5 - Unable to reach 3600 rpm in 30 seconds
Code 6 - Unable to stabilize spin speed in 10 seconds
Code 7 - Unable to maintain spin speed to 0.5%
Code 8 - Unable to uncover Track Zero sensor
Code 9 - Unable to cover Track Zero sensor
Code A - Track Zero interrupter misadjusted
Code B - Shipping zone error, crash stop misadjusted
Code C - Carriage stuck during recal error
Code D - Seek errror during burn-in or recal
Code E - No hall transitions during spin-up
Code F - Unexpected interrupt from processor
Write Data
----------
In recording, to optimize data integrity and meet the error rate
specified, the write data presented by the controller must be pre-
compensated from Track 128 to Track 770.
Track Accessing
---------------
A seek to cylinder 810 will position the read/write heads over the
shipping zone.
A seek to a higher cylinder than 810 will cause a recalibration
sequence in the drive, which will position the read/write heads at
Track Zero.
