Fujitsu M255XK Installation and operation manual

M255XK
51 ;4" Mini-Flexible Disk Drive
Customer
Engineering Manual
FUJITSU
TS021-013087 ... 01
70221
Rev. A

REVISION RECORD
Edition
Date Published Revised Contents
01 April 1987 Initial
Fujitsu America Release
Direct your comments on this publication to:
FUJITSU AMERICA, INC.
3055 Orchard Drive
San Jose, CA 95134 USA
TEL: [phone]
FAX: [phone]
TLX: 230-176207
TWX: [phone]
The
contents of this manual are subject to change without prior notice.
Copyright 1987 FUJITSU AMERICA, INC.
All
Rights Reserved
ii TS-021-013087 ••• 01
70221
Rev. A

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TS-021-013087 ••• 01
iii

SECTION 1 INTRODUCTION
1.1 Scope
1.2 General Description
1.3 Key
Features •
TABLE OF CONTENTS
1.4 Options and Accessories
SECTION 2 SPECIFlCATIONS
Physical Dimension
Storage Capacity •
Disk Mechanism
Track Access Mechanism
INDEX
Pulse. • • • • •
Read/Write Head and Track Specifications
Power
Requirements
Environmental Conditions
Reliability
Regulatory Agency
Certification
Write Protect Mechanism
Page
1-1
1-1
1-2
1-3
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12 I/o Signal
Interface ..
2-1
2-2
2-2
2-3
2~3
2-4
2-4
2-5
2-5
2-6
2-6
2-6
SECTION 3 Tl-EORV OF OPERATIONS
3.1
3.2
3.3
Construction and Functions
3.1.1
Frame Assembly • • • • • • •
3.1.2 Door Opening/Closing and Disk Clamp Mechanism
3.1.3 Spindle Mechanism • •
3.1.4
Read/Write Head and Carriage
3.1.5 Seek Mechanism
3.1.6 Write
Protect Detection •
3.1.7
Track 00 Detection
3.1.8 Index Detection •
3.1.9
Diskette Inserted Detection
3.1.10 Head Load Mechanism
3.1.11 Door Lock Mechanism
Circuit Operations •
3.2.1
Read/Write Circuits •
3.2.2
Control Circuits
3.2.3 Spindle Motor
Test Points
3.3.1 TP1 and TP2 Pre-Amp
•
3.3.2 TP3 Ground •
3.3.3 TP4 and TP5 Di
fferential Amp
3.3.4 TP6
Erase Gate
3.3.5 TP7 Track 00 Sensor
iv
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3-2
3-2
3-3
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3-3
3-3
3-4
3-4
3-4
3-4
3-4
3-8
3-10
3-11
3-11
3-12
3-12
3-12
3-13
TS-DZI-OIJ087 ••• 01

TABLE OF CONTENTS
SECTION 4 MAINTENANCE
4.1 Periodic Maintenance
4.1.1 Inspection and Adjustment
Items •
4.1.2 Field Replaceable Items
4.1.3 Tools Required
for Maintenance
4.2 Maintenance
Precautions
4.2.1 Screw Torque
4.2.2 Screw Lock
4.2.3 Handling Connectors
4.2.4 Additional Maintenance
Precautions
4.3 -Head Cleaning.
4.4 Inspection and Adjustment Procedures
4.4.1
Collet Assembly Centering Adjustment
4.4.2 Bail Inspection and Adjustment
4.4.3 Disk-in Sensor Inspection
4.4.4 Write
Protect Sensor
4.4.5 Disk
Rotational Speed
4.4.6 Head
Contact Inspection and Adjustment
4.4.7 Asymmetry
4.4.B Read Level
4.4.9 Resolution
4.4.10 T
rack Alignment
4.4.11 Track 00 Sensor Inspection and Adjustment
4.4.12 Index Burst Timing Inspection and Adjustment •
4.4.13 Head Load Inspection and Adjustment •
4.4.14 Door Lock Inspection
4.5 Removal and
Replacement Procedures
4.5.1 Head
Carriage Replacement •
4.5.2 Stepping Motor and
Steel Band Replacement
4.5.3 Spindle Motor Replacement •
4.5.4
Collet Assembly Replacement
4.5.5 Sensor Block Replacement
4.5.6 Main Circuit Card Replacement
4.5.7 Write
Protect Sensor Replacement
4.5.8 Bezel Replacement •
4.5.9
Front Lever Replacement
4.5.10 Clamp Cam Replacement
4.5.11 Head Load Replacement
4.5.12 Door Lock Solenoid Replacement •
SECTION 5 MAINTENANCE DRAWINGS AND PARTS LISTS
5.1 Construction •
5.2
Structural Parts Listing
5.3 Screws and Washers
5.4 Main
Circuit Card Components •
5-5
Circuit Card Layout and Schematic Diagrams •
TS-017-082786
••• 01
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FIGURE
2-1
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
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3-12
4-1A
4-1B
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4-22
4-23
4-24
4-25
4-26
4-27
LIST OF ILLUSTRATIONS
External Outline Drawing of Disk Drive
Overall Block Diagram • • •
Tunnel Erase Type Read/Write Head
Read/Write
Circuits •
Typical Read
Circuit Waveforms
Typical Write
Circuit Waveforms •
Control Circui
ts •
Typical Stepping Motor Control
Circuit Waveforms
Location
of Connectors and Test Points
TP1/TP2 Typical Pre-Amp Waveform • •
TP4/TP5 Typical
Differential Amp Waveform
TP6 Typical Erase
Gate Waveform
TP7 Track 00
Detect Waveform
M2553K/54K Revision 2
Circuit Card - Jumper Locations
M2553K Revision 3
Circuit Card - Jumper Locations
M2552K Revision 1
Circuit Card - Jumper Locations
Disk Drive
Orientation During Maintenance
Collet
Shaft Adjustment •
Bail Height Adjustment
Bail Adjustment
Write
Protect Sensor
Head
Contact Inspection •
Asymmetry Measurement • •
Average Read Level Measurement (2F)
Resolution Measurement •
Lobe
Pattern for Track Alignment
Track Alignment Adjustment •
Track 00 Sensor Adjustment
Index Burst Timing
Index Sensor Adjustment •
Head Load SignalllAII
Head Load Signal
IIBII
Head Load Adjustment Screw
Head Unload Signal
II All
Head Unload Signal liB"
Door Lock Solenoid Activated
Door Lock Solenoid Deactivated
Head Carriage Assembly Replacement
Head Cable Routing •
Clamp
Cam Assembly
Head Load Height Adjustment
Door Lock Solenoid
.
Page
.2-1
3-1
3-2
3-5
3-6
3-7
3-9
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vi TS-017-082786
••• 01

FIGURE
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5-5
5-6
5-7
5-8
5-9
5-10
5-9
5-10
TABLE
LIST
OF ILLUSTRATIONS (Continued)
Top View
of Disk Drive (View 1)
Top View
of Disk Drive (View 2)
Bottom View of Disk Drive
Rear View of M255XK
Exploded View Drawing
M2552K Revision 1
Circuit Card Layout
M2553/54K Revision 2 Circuit Card Layout •
M2553 Revision 3
Circuit Card Layout •
Interconnec t Diagram
M2552K Revision 1 Schematic Drawing
M2553/54K Revision 2
Schematic Drawing
M2553K Revision 3
Schematic Drawing
UST OF TABLES
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
MFM Recording Storage Capacity
Disk Mechanism
Track Access Mechanism
INDEX
Pulse. • • • • •
Read/Write Head and Track Specifications
Power Supply Requirements
Environmental Conditions
Reliabili
ty
Regulatory Agency Certification
Interface Signal -Pin Designation
4-1 Inspection and Adjustment Items
4-2 Field Replaceable Items
4-3 Maintenance Tools
4-4 Screw Size and Torque •••••••
4-5A M2553K/54K Revision 2 Circuit Card Jumper Definitions
4-5B M2553K Revision 3 Circuit Card Jumper Definitions
4-5C M2552K Revision 1 Circuit Card Jumper Definitions
5-1 M255XK Assembly Chart
5-2 Listing of Structural Parts •
5-3 Listing of Screws and Washers • •
5-4 Listing of Main Circuit Card Components
TS-017-082786 ••• 01 vii
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5-10

1.1 SCOPE
SECTION 1
INTRODUCTION
This manual explains
the service procedures for the FUJITSU M255XK Family of
51" Mini Flexible Disk Drives.
This Section gives
an overview of the Disk Drives.
Section 2 provides
specifications.
Section 3 explains the drive's operations
Section 4
details maintenance procedures
Section 5 contains
parts lists and mechanical and schematic drawings.
1.2 GEI\ERAL DESCRIPTION
M255XK disk drives
offer superior performance, reliability and construction in
Half-Height 5i" Flexible Disk Drive technology.
Industry
standard 51" (130mm) diskettes are used as the storage medium. These
drives have an independently addressed Read/Write head
for each side of the
diskette.
FM (Frequency Modulation) or MFM (Modified Frequency Modulation) recording
methods
are acceptable.
There are three Models in the M255XK Family:
M2552K -This model
records 5,922 flux transitions per il1ch and has a per disk
unformatted storage capacity of 1 Mbyte with MFM Encoding or 500
Kbytes with
FM Encoding.
With a 16
sector format (256 bytes per sector), the M2552K emulates a
double density/double sided, 96
track per inch 51" industry standard
disk drive.
M255JK -This model
records 9,646 flux transitions per inch and has a per disk
unformatted storage capacity of 1.604 Mbytes with MFM Encording or
802 Kbytes with FM'Encording.
With a 15
sector format (512 bytes per sector) the M2553K emulates a
double density/double sided, 96
track per inch (1.2 MByte) industry
standard 51" disk drive.
M2554K -This model
has a host system controlled interface line (pin-2) that
allows operation at either 300 RPM, or 360 RPM.
TS-021-013087
••• 01 1-1

M2554K (Continued)
When
set at 300 RPM the M2554K records 5,922 flux transistions per
inch (similar to a M2552K) and has a per disk unformatted storage
capacity of 1 Mbyte with MFM Encording or 500 Kbytes with FM
Encording.
When
set at 360 RPM, the M2554K records 9646 flux transitions per
inch (similar to the M2553K). and has a per disk unformatted storage
capacity of 1.604 Mbytes with MFM Encording or 802 Kbytes with FM
Encoding.
With
MFM recording methods, the data transfer rate is:
M2552K -250 Kbi
ts per second
M2553K -500 Kbi
ts per second
M2554K -250
Kbits per second at 300 RPM
-500
Kbits per second at 360 RPM
Spindle
motor speed is:
M2552K 300 RPM
M2553K -360 RPM
M2554K -Host
system selected (via an interface signal line) for 300 or 360 RPM
On all Models,
Track density is 96 TPI and there ere 80 cylinders/160 tracks per
disk. Track to track access time is 3 milliseconds, plus a 15 millisecond settling
time. Average access time, including settling time, is 94 milliseconds.
Except for the di fferences .listedabove, performance of the units is identical.
Refer to the M255XK Product Description Manual for an overview of the M2552K,
M2553K, and M2554K Mini
Flexible Disk Drives.
1.3 KEY FEATURES
o
Half-Height (1.625 inches)
o Industry
standard flexible disk drive mounting
o Industry
standard flexible disk drive interface
o Vertical clamping mechanism
o
Up to 1.604 Mbytes of unformatted storage capacity
o The M2554K may be set by the host computer to function as a 1.6 Mbyte
or 1.0 Mbyte capacity disk drive (allowing a single source for two
products)
o High quality and
reliability
o FUJITSU AMERICA support
1-2 TS-021-013087
••• 01

1.4 OPTIONS AND ACCESSORIES
o
Automatic Diskette Eject
Ejects the diskettes from the disk drive, when the door lever is released.
The disk drive is set to the Not Ready State (when the diskette is
ejected).
o Head Load Solenoid
Allows
the host system to Load/Unload the Read/Write heads in the disk
drive via an
interface signal line.
o
Auto-Rezero
Rotates the diskette (to full speed) and retracts the Read/Write heads to
Track 00, whenever power is turned-on.
o Door Lock
Allows
the door lever to be locked, to prevent media removal, when the
drive is selected or when In Use is selected.
o Door Switch
Allows
the Ready signal to be active whenever the door is closd
regardless of Drive Selection.
TS-021-0l3087 ••• 01
1-3

2.1 PHYSICAL DIMENSIONS
SECTION 2
SPECIFICATIONS
Refer to the following drawing (Figure 2-1).
Height: With Bezel = 1.65 ~0.02 inches (42 ~0.5mm)
Without Bezel = 1.62 ~ 0.02 inches (41 ~ 0.5mm)
Width: With Bezel =
5.B3 ~0.02 inches (l4B ~0.5mm)
Without Bezel = 5.75 ~0.02 inches (146 ~0.5mm)
Depth*: With Bezel = B.19 ~0.02 inches (20B ~0.5mm)
Without Bezel = B.OO ~0.02 inches (203 ~0.5mm)
* Without power or interface cable connector
Weight: 3.10 pounds (1.2 Kg) maximum
Signal Power
1.6"
(41mm)
10
Connector Connector
.5.5" (139.7mm)
•
(JOmm)
0>0>
\ S.7S" (l46mm) I
\ 1.8" 10.06 1.6" /
1\ (45.5mm) (40mm) I
r·\L_~ .. _} ... V: ...... \L.-l.J/]
, '~ ..
, .
. .
, .
,
.. ' PCB ·
·
I
•
"'N = = : ·
I
.... _; :
NN
.... c
ClCl
NV,
3 3
3 3
~~
,
• I
:.--"'~
• I
.... ___________ ..J
11 5.82" (~48.0mm) /
1.S"
1.9" '/
r (J8mm)' (47mm) I/
Figure 2-1 External Outline Drawing of Disk Drive
TS-021-0130B7 ••• 01 2-1
o
::
~
II)
-
o
...
2:
II

2.2 STORAGE CAPACITY
Table 2-1
MFM Recording Storage Capacity*
300 RPM 360 RPM
MODEL NUMBER M2552K M2553K M2554K M2554K
UNFORMATTED:
Each
Diskette
1.000MB 1.604MB 1.000MB 1.604MB
Each
Track
6.25KB 1O.416KB 6.25KB 10.416KB
16-SECTOR FORMAT
Each
Diskette
655.36KB -655.36KB -
Each Track
4.096KB -4.096KB -
Each Sector 256 Bytes -
256· Bytes -
FORMATTED 15-Sectors
Each Diskette
-1.229MB -1.229MB
Each
Track
-7.680KB -7.680KB
Each
Sector
-512 Bytes -512 Bytes
BITS PER INCH 5922 9646 5922 9646
TRACKS
PER INCH 96TPI 96TPI 96TPI 96TPI
I OF TRACKS 160 160 160 160
I OF CYLINDERS 80
80 80 80
TRANSFER RATE 250KBS 500KBS 250KBS 500KBS
* =One-half
the given Storage Capacity values with FM Encoding.
2.3 DISK MECHANISM
Table 2-2 Disk Mechanism
300 RPM 360 RPM
MODEL NUMBER M2552K M2553K M2554K M2554K
SPINDLE SPEED 300
RPM 360 RPM 300 RPM 360 RPM
AVERAGE LATENCY
TIME
100 msec 83.3 msec 100 msec 83.3 msec
SPEED VARIATION ='1.5% Maximum Long
Term & Instantaneous
ROTATIONAL CONTROL
AC Tachometer Controlled Frequency Servo
SPINDLE MOTOR TYPE
Direct Drive DC Brushless Motor
SPINDLE START
TIME
400 milliseconds maximum
TS"()21-D1JOB7 ••• 01

2.4 TRACK ACCESS MECHANISM
Table 2-3 Track Access Mechanism
STEPS
PER TRACK 1
step
ACCESS TIME
Track to Track 3 msec
(Without
settling time)
Average (Inner-track)
94 msec
(With
settling time)
POSITIONING ACCURACY Within
.:t 20 micrometers at 96 TPI (Track 32),
using a Standard
Test Diskette at 740 F (230 C)
.:t20 at 40-60% Relative Humidity
HEAD SETTLING
TIME
15 milliseconds maximum, does not include track
access time
HEAD CARRIAGE DRIVE
4-Phase Stepper Motor and Steel Belt
TRACK 00 DETECTION LED and
Photo-transistor Detection
Mechanical stop on head carriage
2.5 INDEX PULSE
Table 2-4 INDEX Pulse
INDEX DURATION 1
to 8 milliseconds (use the leading edge)
TIME BETWEEN INDEX 200.00 milliseconds .:t 1.5% at 300 RPM
PULSES 166.67 milliseconds
.:t 1.5% at 360 RPM
INDEX ACCURACY 200.:t 150 microseconds from
the beginning
of
the INDEX hole on a standard test disket te
FIRST INDEX PULSE 400 millisecond nominal
after Motor Start
NUMBER OF PULSES One (1) INDEX Pulse
per disk revolution
INDEX DETECTION
LED and Photo-transistor
TS-021-013087 ••• 01
2-3

2.6 READ/WRITE .-EAD AND TRACK SPECIFICA nONS
Table 2-5 Read/Write Head and Track Specifications
TYPE OF R/W HEAD Gimbal supported with Tunnel Erase
NUv1BER
OF R/W HEADS Two (one on each side of the Diskette)
R/W HEAD TRACK
WIDTH 0.165mm standard
0.155 !: 0.0l5mm after Tunnel Erase:
ERASE HEAD
WIDTH
0.095mm standard
WRITE/READ -ERASE GAP 0.85 !:0.05mm -M2552K
0.58 !:0.05mm -M2553K and M2554K
WRITE/READ GAP AZIMUTH O!: 26' -M2552K
Standard Test Diskette
o!:18' -M2553K and M2554K
TRACK RADIUS (Maximum)
Track 00 (External Lap): 57.150mm Side 0
55.033mm Side 1
Track 79 (Internal Lap): 36.248mm Side 0
34.131mm Side 1
2.7 POWER REQUIREMENTS
Table
2-6 Power Supply Requirements
+12
VOLTS DC !:5% allowable variance during
read/write operations and !:10%
at other times
200 millivolt maximum peak-to-peak ripple voltage
(including noise spikes)
0.22 Amperes average
current draw
0.60
Amperes maximum average current draw
0.90 Amperes peak
current draw (Spindle Motor start-up)
0.07 Amperes maximum current draw (Spindle Motor idle)
+5 VOLTS DC !:5% allowable variance .
100 millivolt maximum peak-to-peak ripple voltage.
(including noise spikes) -
0.29 Amperes average
current draw
0.33 Amperes maximum
current draw (Spindle Motor idle)
0.50 Amperes maximum
average current draw (standby mode)
0.60 Amperes maximum
average current draw (operating)
2-4 TS-021-013087
••• 01

2.8 ENVIRONMENTAL CONDITIONS
Table 2-7 Environmental Conditions
OPERATING STORAGE TRANSPORT*
Ambient
Temperature
39 to 1150 F -7.6
to 1400 F -40 to 1490 F
Non-condensi
ng
(4 to 46
0 C) (-22
to 600 C) (-40 to 650 C)
Temperature Gradients 590 F/Hour Not specified 860 F/Hour
(Maximum) (150 C/Hour) (300 C/Hour)
Relative Humidity
20 to 80% Max. 10 to 90% Max. 5 to 95% Max.
(Maximum Wet-Bulb) 840 F 1040 F 1130F
Non-condensing (290 C) (400 C) (450 C)
Vibration Tolerance 0.50G 55Hz Not Specified 2.0G 100Hz
(Maximum) 0.25G
55 to 150HZ
Shock Tolerance lOG 10msec
(Maximum) Not Specified 40G 10msec
* Packed in designated
crates with conditions conforming to JIS-Z0200 -Provisions
for Correctly Packed Freight Testing Methods; Level II.
When transport takes place over an extended period (such as trans-oceanic by
ship)
the Storage Environmental Conditions apply.
2.9 RELIABILITY
Table 2-8 Reliability
MEAN
TIME BETWEEN FAILURES
(MTBF) 11,000 Power-on hours, with
25% duty cycle
MEAN TIME TO REPAIR
30 Minutes Maximum to subassembly level
(MTTR)
PERIODIC MAINTENANCE Not required. Head Cleaning
if necessary
PRODUCT LIFE 5
years
DISK LIFE Three
times 106 passes/track minimum
DISKETTE INSERTIONS One
times 104 insertions minimum
DATA ERROR RATES:
Soft Read Error Rate One per 109 bits (with up to 2 re-reads)
Hard Read
Error Rate One per 1012 bits (with more than 2 re-reads)
SEEK ERROR RATE One
per 106 seeks
TS-021-013087
••• 01
2-5

2.10 REGULATORY AGENCY CERTIFICATION
Table 2-9 Regulatory Agency
Certification
FCC (Federal Communications Commission) CFD 75U255X
See FCC
Statement on inside of back cover.
UL (Underwriters Laboratories)
UL EB729-1
CSA (Canadian Standards Association) LR 60527-1
2.11 WRITE PROTECT MECHANISM
Diskette's Write
Protect Notch is detected with a Light Emitting Diode (LED)
and
Photo-transistor.
2.12 I/O SIGNAL INTERFACE
Complete I/o control and data interface specifications are given in the M255XA
Product Description Manual. Table 2-10 lists the Interface Pin Designations.
Table 2-10
Interface Signal - Pin Designation
Signal-Pin
Return-Pin
Signal Name
Direction
Number Number
HD (Hi Density)/LSP (Speed)* Out/In 2 1
IN USE/HEAD LOAD Input 4 3
-DRIVE SELECT 3 Input 6 5
-INDEX PULSE Output B 7
-DRIVE SELECT 0 Input 10 9
-DRIVE SELECT 1 Input 12
11
-DRIVE SELECT 2 Input 14 13
-MOTOR-ON Input 16 15
-DIRECTION SELECT Input IB 17
-STEP Input
20
19
-WRITE DATA Input
22 21
-WRITE GATE Input
24
23
-TRACK 00 Output
26 25
-WRITE PROTECT Output
2B
27
-READ DATA Output 30
29
-SIDE ONE SELECT Input 32 30
-READY/DISK CHANGE Output 34 33
* Pin 2 is unused in
the M2552K
2-6 TS-021-0130B7
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SECTION 3
THEORY OF OPERATIONS
3.1 CONSTRUCTION AND FUNCTIONS
M255XK drives
are constructed with high precision components and assembled with
automated techniques. This ensures that the industry standard 5i" flexible mylar
disk, used
as the recording medium, has the ability to interchange data with other
5i" disk drives.
As with all high precision equipment, excessive shock and
vibration must be
avoided and only
trained maintenance personnel should service the unit.
Refer to the Overall Block Diagram in Figure 3-1.
T5-021-013087 ••• 01
!fapetic bead
Track 00 sensor
~wi~~r---J
,---Door lock soleuoid
,---File protect sensor
r----File protect sensor LED
,--Disk
IDdex seasor LFD
Figure J-1 OveraD Block Diagram
3-1

3.1.1 Frame Assembly
The
frame assembly is the skeleton on which the mechanisms and circuit boards
are mounted. This aluminum die cast chassis ensures the drive has the strength,
accuracy and expansion ratio required for stable disk drive operations.
3.1.2 Door Opening/Closing and Disk Clamping Mechanism
The door opening/closing mechanism includes
the clamp spring (flat spring), front
lever, and set arm. The disk clamp mechanism (Collet) is moved up and down by
the end of the set arm. When a diskette is inserted and the front lever is closed,
the collet enters the opening in the center of the disk, and presses against the
spindle to ensure the disk is accurately clamped into position.
3.1.3 Spindle Mechanism
The disk
rotating system is comprised of the spindle and spindle motor. The
spindle
motor is a direct spindle coupled outer rotor type DC brushless motor with
a service life
of 20,000 or more hours of continuous operation. The spindle motor
rotates at 300 or 360 RPM and maintains a constant speed, even with load and
temperature fluctuations, by using feedback signals from an AC tachometer built
into the motor.
The spindle and
collet are precisely aligned to prevent injury to the center hole of
the disk and to allow accurate centering of the disk. This also ensures the heads
and disk come into
contact at exactly the correct location.
3.1.4
Read/Write Head and Carriage
The flat shaped read/write heads are supported by a gimbal. The heads straddle
the disk and are mounted on the carriage. The read/write heads are designed to
obtain maximum playback from the disk, with minimum head to disk contact
pressure.
Refer to Figure 3-2. The tunnel erase read/write heads have a read/write gap to
record and playback data, and a tunnel erase gap to trim the edges of each track
immediately after it is written.
Rea.d/Write core
_.Direc:tioa of
disk rotation
Erase core
Figure 3-2 Tunnel Erase Type Read/Write Head
3-2 T5-021-013087
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