M 8 4 1 2 MINISCRIBE
NO MORE PRODUCED Native| Translation
------+-----+-----+-----
Form 3.5"/HH Cylinders 308| | |
Capacity form/unform 10/ 13 MB Heads 4| | |
Seek time / track 50.0/15.0 ms Sector/track 17| | |
Controller MFM / ST412 Precompensation 65535
Cache/Buffer KB Landing Zone 307
Data transfer rate 0.625 MB/S int Bytes/Sector 512
0.625 MB/S ext
Recording method MFM 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 W Shock g 10 | 70
seek 10.0 W Rotation RPM 3600
read/write 11.2 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. 8212/8412/8425/8438 PRODUCT MANUAL P/N 1010 REV. T
Universal I PCBA
+---------------------------------------------------------+
| SEL |XX
| J19++ +-+ |XX
| ++ | | |XX P2
| J18+--+ | | |XX
| +--+ +-+ +-+ |XX
| J13| | |
| +-+ ++ |XX
|+--J16 || |XX P1
|+--+ RP1|| |XX
| J15---+ Terminator|| |XX
| J17+-+ +---+ ++ |XX
| +-+ |XX
| |XX
| |XX
| |
+--------------------------------------------------xxxxxx-+
Power xxxxxx
Earlier versions of PCBA do not contain J13, J15, J17, J18, J19, and
the LED is soldered directly into PCBA.
Universal II PCBA
+---------------------------------------------------------+
| SEL |XX
| J19++ +-+ |XX
| ++ | | |XX P2
| J18+--+ | | |XX
| +--+ +-+ +-+ |XX
| J13| | |
| +-+ ++ |XX
| || |XX P1
| RP1|| |XX
| Terminator|| |XX
| J17+-+ ++ |XX
| +-+ |XX
| |XX
| |XX
| |
+--------------------------------------------------xxxxxx-+
Power xxxxxx
**********************************************************************
J U M P E R S
**********************************************************************
MINISC. 8212/8412/8425/8438 PRODUCT MANUAL P/N 1010 REV. T
Jumper setting
==============
x = Jumpers set at factory
Customer options are limited to the drive select address (SEL) and
burn-in mode on drives dhipped to mid-1986. On newer drives there are
additional options which may be selected. On all drives normal opera-
tion is achieved no jumper or trace modifications.
SEL 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 1
of the SEL 1 header must be repositioned to one of the other three
rows corresponding to the desired drive select number.( Row 1,
corresponding with Drive Select 1, is the topmost row when the inter-
connected column of pins is on the right.)
+----+
x 1 |xxxx| Drive select 1.
2 |O O|
3 |O O|
4 |O O|
*5 |O O|
+----+
* Universal II PCBA does not contain position 5.
Universal PCBA Jumper Functions
-------------------------------
On PCBA's with P/N 30085120X, the following jumpers are available:
J13B Low power option 1
------------------------
OPEN Current from stepper motor is removed after no activity
for 30 seconds.
J13C Low power option 2
------------------------
OPEN Seek to ship zone is performed before stepper power is
removed. Note that J13B has to be open also.
J15 Seek complete
------------------
OPEN Delays seek complete by 3 milliseconds.
J17 Daisy-Chained
------------------
CLOSED Allows data cable to be daisy-chained.
J18 LED
--------
Normally 1 and 2 are jumpered. If 2 and 3 are jumpered, this
connects the LED drive select.
J19 UNSAFE/MOTOR ON
--------------------
CLOSED Asserts -UNSAFE through +MOTOR ON.
J21 Voltage
------------
Normally 2 and 3 are jumpered. If 1 and 2 are jumpered, a
voltage fault will occur at a higher voltage.
The following table depicts how drives with Universal I PCBA and the
Universal II PCBA are shipped from the factory.
UNIVERSAL I
Module J13A J13B J13C J15 J17 J18 1-2 J18 2-3 J19
---------------------------------------------------------------------
07 OPEN CLOSE CLOSE CLOSE CLOSE CLOSE OPEN OPEN
08 OPEN CLOSE CLOSE CLOSE CLOSE CLOSE OPEN OPEN
UNIVERSAL II
Module J13A J13B J13C J17 J19 J21 2-3 J21 1-2
------------------------------------------------------------
05 OPEN CLOSE CLOSE CLOSE OPEN CLOSE OPEN
22 OPEN CLOSE CLOSE CLOSE OPEN CLOSE OPEN
23 OPEN CLOSE CLOSE CLOSE OPEN OPEN CLOSE
24 OPEN CLOSE CLOSE CLOSE CLOSE CLOSE OPEN
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 A to determine
its state (open or closed). Briefly, Jumper A (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 A. If open, go to normal operation. If closed,
continue to Step 4.
4. Display code level (5 bits), e.g. 00001
5. Test Jumper A level. 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. 8212/8412/8425/8438 PRODUCT MANUAL P/N 1010 REV. T
Notes of installation
=====================
Installation direction
----------------------
horizontally vertically
+-----------------+ +--+ +--+
| | | +-----+ +-----+ |
| | | | | | | |
+-+-----------------+-+ | | | | | |
+---------------------+ | | | | | |
| | | | | |
| | | | | |
+---------------------+ | +-----+ +-----+ |
+-+-----------------+-+ +--+ +--+
| |
| |
+-----------------+
Drive Orientation
-----------------
The drive may be mounted in any attitude.
Mounting Configuration
----------------------
The Miniscribe 8212, 8412, 8425 and 8438 quarter size drives are
designed to be used in applications where the unit may experience
shock and vibration at greater levels than larger and heavier disk
drives.
Two features which allow greater shock tolerance are the rugged media
and shock mounts. To take full advantage of the shock mounts,
however, it is necessary to provide a minimum of 0.1 inch clearence
on both the top and sides of the drive. This clearence allows for
movement of the drive during acceleration.
The drive is mounted using 6-32 screws, 1/8 inch maximum penetration.
The customer should allow adequate ventilation for the drive to en-
sure reliable drive operation over the operating temperature range.
Mechanically isolated mounting points
-------------------------------------
Four (4) side mounting and four (4) base mounting points are
provided to the customer. Each mounting point is mechanically isola-
ted from the head-disk assembly.
Cabling
-------
Connect interface cables with connector P1, P2 and P3 to J1, J2 and
J3 respectively. Iff multiple drives are to be interconnected, remove
the terminator packs in all but the last drive of the daisy chain.
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
Terminators
-----------
Each drive is shipped with a terminator pack providing the 220/330
ohn termination for the Control Input Signals. If multiple drives are
configured in a daisy chain configuration, the terminator pack must
be removed from all except the last unit on the daisy chain.
P1 Control Signal Connector
---------------------------
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 circuit side
of the Printed Circuit Board. A key slot is provided between pins 4
and 6.
The recommended mating connector (J1) is AMP Ribbon Connector, P/N
88373-3.
P2 Data Signals Connector
-------------------------
Connection to P2 is through a 20 pin edge connector. The pins are
numbered 1 through 20 with the odd pins located on the circuit 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 DC Power Connector
---------------------
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.
+------------+ 1 = +12 Volts DC
| 4 3 2 1 | 2 = +12 Volts Ground Return
+------------+ 3 = + 5 Volts Ground Return
4 = + 5 Volts DC
Electrical Interface
--------------------
The interface to the MiniScribe 8212, 8412, 8425 and 8438 can be
divided into three categories, each of which is physically separated:
Control Signals, Data Signals and DC Power.
All control Signals are digital in nature (open collector TTL), and
provide signals either to the drive (input) or signals to the
collector (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.
**********************************************************************
F E A T U R E S
**********************************************************************
MINISC. 8212/8412/8425/8438 PRODUCT MANUAL P/N 1010, REV. T
Introduction
------------
The Miniscribe 8212, 8412, 8425 and 8438 are half-height random
access 95 mm rigid media disk drives employing Winchester technology.
The drives utilize a rack-and-pinion actuator, microprocessor
control, and open stepper head positioning.
The drives feature power up diagnostics and buffered seek. Models
8212, 8412 and 8425 have a data transfer rate of 5 Megabit/Sec, while
the 8438 features a 7.5 Megabit/Sec data 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) | 8438 | |
| 8212,8425 | 8412 |
----------------------------+-----------+----------+
Average Single Track * | 15 ms | 15 ms |
Average | 68 ms | 50 ms |
Maximum | 152 ms | 120 ms |
Average Latency | 8.33 ms | 8.33 ms|
----------------------------+-----------+----------+
* Worst Case Single Track Seek: 15.4 ms.
Reliability and Maintenance
---------------------------
MTBF 20,000 hours (continuous operation) at 35*C
MTTR 30 minutes
Preventive Maintenance None
Component Design Life 5 years
Media Defect Criteria
---------------------
Models 8212 & 8412 Models 8425 & 8438
-------------------- ---------------------
6 defects/surface maximum 6 defects/surface maximum
10 defects maximum 20 defects maximum
2 bytes or less in length 2 bytes or less in length
Cylinder Zero Defect Free Cylinder Zero and one Defect Free
Magnetic Field
--------------
The externally induced magnetic flux density may not exceed 3 Gauss
as meaured at the disk surface.
Drive Mechanism
---------------
A brushless DC direct drive motor rotates the spindle a 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 live, a clean, above
atmospheric pressure environment for the heads and disks.
Head Positioning Mechanism
--------------------------
Two (2) read/write heads on the Model 8212 and four (4) read/write
heads on the Models 8412, 8425 and 8438 are supported by a carriage
mechanism coupled to the stepper motor through a rack-and-pinion
motion translator.
Track Zero Detector
-------------------
The Track Zero Detector resides on the stepper motor. This optical
sensor consists of a light source (activated only ehen a seek is
initiated) and a receiver which when blocked by an interrupter on the
motor shaft, indicates one of several logical Track Zero positions.
The microprocessor determines the physical location of Track Zero
from the redundant logical Track Zeros.
