OEM Thinline TM50-1 Service manual

OEM
UP~RATING AND S~RVICE MANUAL
TM5U-l AND TM5U-2 THINLIN~TM
5-1/4-INCH fLEXIHLE DISK DRIV~S
48 TRACKS PER INCH
TAN DON CORPURATIUN
2U320
PRAIRIE STREET
CHATSWURTH, CALIfURNIA 91311 ~CUPYRIGHT 1983 TANDUN CURPURATIUN

This document, and
Tandon Corporation
or in part, without
NOTICE
the information contained
and may not be duplicated
the prior written approval
herein, is copydC)ht by
or repr.oduced, in whole
of Tandon Corporation.
This document 1S intended to provide tilE: user
information adequate for the efficient installation,
service of the equipment involved.
with cletailec]
operation, and
However, while every effort has been made to keep the informati,on
contained herein current and accurate as of the date of publication,
no C)uarantee is given or implied as to its accuracy.

Section
Number
SECTION 1
1.1
1.2
1.3
1.4
1.5
SECTION 2
2.1
2.2
2.3
2.4
SECTION 3
3.1
3.2
3.3
3.4
3.5
3.6
CONTENTS
'Ii tle
GENERAL DESCRIPTION
Introduction •
Scope Of The Document
Purpose Of The Drive
Major Features
Write Protect
Daisy Chain Capability
Internal Trim Erase
Industry Standard Interface Compatibility
Track 0 Sensor •
Index Sensor .•.
Activity Indicator
Compact Size • •
Functional Description
Physical Description
PRODUCT SPECI!"ICATIONS
Introduction . ...•..•.
Mechanical Specifications •.•
Electrical and Operational Specifications
Reliability Specifications
Environmental Specifications
OPERATION
Introduction •
Unpacking The Drive
Preinstallation Checkout
Mounting The Drive
Dust Cover . • • •
Cooling
Interface Connections
Input Control Lines
Output Control Lines
Typical Interface Characteristics
D. C. Power . . . . . .
Drive Address and Option Patching
DSO Through DS3 Jumpers
MX Jumper . • • .
i
Page
Number
1-1
1-1
1-1
1-1
1-1
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-2
1-3
2-1
2-1
2-1
2-1
2-1
3-1
3-1
3-1
3-2
3-2
3-2
3-3
3-4
3-6
3-7
3-7
3-8
3-8
3-8

Section
Number
3.7
SECTION 4
4.1
4.2
4.3
4.4
4.5
4.6
SECT ruN 5
5. 1
5.2
5.3
5.4
5.5
CONTI<;NTS
'Ii tle
Motor Select ,Jumper
Write Protect (WI)
Head Type (W2, W3)
W4 Through W8
Side Select (W9)
Motor On (WI)
Diskettes • • •
Loadiny The Diskette
Write Protect Tab
Diskette Handling and Storage
THEORY Of OPERATION
Introduction
Data Recording .
Components Of The Drive
Generate and Interpret Control Signals
Index Sensor
Write Protect Switch
Track 0 Sensor
Drive Select
Read/Write Head Positioner
Step and Direction
Stepper Motor Control
Stepper Motor.
Read/Write Data
Read/Write Head Assembly
Side Select Circuits
Write/Erase Circuits
Read Data Circuits
Spindle Control . . • .
Spindle Motor and spindle Assembly
Spindle Motor Enable Circuit
Spindle Motor Control Circuit
Diskette Enabled Switch (Door Lever)
MAINTENANCE CHECKS AND ADJUSTMI<;NTS
Introduction
Visual Inspection
Equipment Required
Power Drive Select Check
Write Protect Switch Check and Adjustment
write Protect switch Check
Write Protect switch Adjustment •.
Drive Motor Speed Check and Adjustment
Drive Motor Check .
Drive Motor Adjustment
ii
Paye
Number
3-11
3-11
3-11
3-11
3-11
3-12
3-12
3-12
3-13
3-13
4-1
4-1
4-4
4-4
4-4
4-5
4-5
4-6
4-7
4-7
4-8
4-8
4-8
4-8
4-8
4-9
4-12
4-12
4-13
4-13
4-14
4-14
5-1
5-1
5-2
5-3
5-4
5-4
5-4
5-4
5-4
5-5

Section
Number
5.6
5.7
5.8
5.9
5.10
5.11
5.12
5.13
SECTION 6
Title
Radial Track Aliunment Check and Aejjustment
Radial Track Aliynment Check .
Radial Traok Aliynment Ad]ustmerlt
Index Checks and Adjustment
Index-To-J)ata Pulse Ctlecks
Index Sensor Adjuslment
Az i mu th Check .
Track 0 Sensor Check and Adjustment
Track 0 Sensor Check •
Track 0 Sensor Adjustment
Track 0 Stop Adjustment
Head Output Check .
Cone Centeriny Check
Compliance Check and Adjustment
(Single-Sided Drives)
Compliance Check .
Compliance Adjustment
REMOVAL AND INSTALLATION
Control and Data Circuit Board •
Servo Circuit Board
Chassis Shield, Control and Data Circuit Board
Diskette Lever Assembly
Front Panel
Power Input Fluy and Hracket
Write Protect Switch
Write Protect Sensor
Stepper Band .
Stepper Motor
Upper Plate Assembly
Track 0 Sensor and Track 0 stop \Ilock
Head Module
Drive Helt .
Drive Motor
Numbc} r
5-6
5-7
5- iU
5-10
5- 11
5-13
5-13
5- l5
5-[5
';-16
5-l6
5- 17
5-1',)
5-2U
5- 2U
5- 2.l
6-2
6-2
6-3
6-3
6-)
6-5
6- 6
6-7
6-(j
6-1 U
6-12
6-14
6-16
6-17
6-18
APPENDIX A Recommended Spare Parts and Major Assemblies
APPENDIX B Circuit Board Schematics and Drawings
iii
A-I
B-1

Fi(:J ure
Number
1-1
2-1
3-1
3-2
3-3
3-4
3-5
3-6
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
ILLUSTRATIONS
Ti tle
Disk Drive
Disk Drive Outline Drawing.
81ectrical Interface Characteristics
Control and Data Timing Requirements
Logic Board With Prograrrunable Shunts
and Option Patching Locations
Recording Media
Write Protect Tab •.•.
Diskette Care and Handling
81ectromagnetic Core .
PM Recording Magnetization Profiles
Read Timing Diagram
Interconnect Block Diagram
Soft Sectored Index Pulse
Track 0 Timing •
Write Data Circuit Block Diagram
Write Operation Timing Diagram
Read Circuit Block Diagram ••.
Servo Circuit Board ••
Logic Circuit Board With Test Points
Write Protect Switch Adjustment
Location Of R15 Speed Control Potentiometer
Bottom View Of Drive ••..
Hub Center Line and Track Location .•••
Cats Eye Patterns
Stepper Motor Retaining Screws and Camming Bars
Index-To-Data Pulse ••••
Index Sensor's Retaining Screw and Adjustment
uptimum Head Azimuth Alignment
Head Azimuth Alignment Of Acceptable
Lower Limits •. . ..••.
Head Azimuth Alignment Of Acceptable
Upper Limits . • •••
Track 0 stop . • • •
Upper Arm and Compliance Spring
Control and Data Circuit Board
Servo Circuit Board
Diskette Lever Assembly
Power Input Plug and Bracket
Stepper Band •
Stepper Motor • . • .
Upper Plate Assembly • • • •
Track 0 Sensor and Stop Block
Drive Motor •••
iv
Pagl~
Number
1-4
2-2
3-7
3-')
3-10
3-12
3-13
3-14
4-1
4-2
4-2
4-3
4-5
4-6
4-10
4-11
4-13
4-14
5-2
5-5
5-6
5-6
5-7
5-8
5-10
5-11
5-12
5-14
5-14
5-15
5-18
5-21
6-4
6-4
6-4
6-5
6-10
6-11
6-13
6-15
6-19

Table
Number
2-1
2-2
2-3
3-1
3-2
TAHLES
Title
Electrical and Operational Specifications
Reliability Specifications.
Environmental Specifications •
Drive Interface Lines and Pin Assiynments
D. C. Power Connector Pin Assignments
v
Paye
Number
2-3
2-4
2-5
3-3
3-8

SECTION 1
GENERAL DESCRIPTION
INTRODUCTION
This document provides required information in order to evaluate
and incorporate Tandon's disk drive into a system.
Tandon Corporation's Model Number TMSO-l and TMSO-2, S-1/4-inch
flexible drives are compact, low profile drives that may be installed
in only one-half the space normally required. They are compact data
storaye devices that use an ANSI-compatible, industry standard, 5-1/4-
inch diskette.
Model Number TMSO-l and TMSO-2 drives each 48 tracks per inch. The
TM50-2 is a double-sided recording device.
Both drives are capable of reading and writing in single-density
format on a diskette, using a proprietry read/write head patented by
Tandon. The drives have a double density capability when a t10dified
Frequency Modulated (MFM) or other appropriate recording technique is
used. Encoding and decoding of the data is done by the
user's controller.
1.1 SCOPE OF THE DOCUMENT
This document contains the
specifications, mounting and
typical timing characteristics
major features, physical
power requirements, the
of the TMSO-l and TMSO-2
and functional
interface, and
drives.
In addition, there is a theory of operation, checks and adjustment
procedures, replacement procedures, assembly drawing~ and schematics.
1.2 PURPOSE OF THE DRIVE
The TMSO-l and TMSO-2 drives are rotating disk memories designed for
random access data entry, storage, and retrieval applications.
Typical applications include intelligent terminal controllers,
microcomputers, word processing systems, data communication systems,
error logging, program loading, and point-of-sale terminals.
1.3 MAJOR FEATURES
write Protect
When a write protected diskette is inserted into the drive, the write
electronics are disabled.
1-1

Daisy Chain Capability
The drive provides the address selection and gating functions
necessary to daisy chain a maximum of four units at the user's option.'
The last drive of the daisy chain terminates the interface. The
terminations are accomplished by a resistor array plugged into a DIP
socket.
Internal Trim Erase
The drive provides the control signals necessary for proper trim
erasure of data.
Industry Standard Interface Compatibility
The drive is compatible with controllers that use an industry standard
interface.
Track 0 Sensor
The Track 0 sensor is provided to generate a logic level at the drive
interface, indicating that the read/write head is positioned at the
outermost track.
Index Sensor
An index sensor is provided to generate electrical pulses at the drive
interface coincident with sensing Index/Sector holes on the diskette.
Activity Indicator
An activity indicator, located on the front panel, is automatically
illuminated when the drive is selected.
Compact Size
The reduced height of the drive enables it to occupy only one-half the
mounting space required for a conventional drive.
1.4 FUNCTIONAL DESCRIPTION
The drives are fUlly self-contained, and require no operator interven-
tion during normal operation. Each drive consists of a spindle drive
system, a head positioning system, and a read/write system.
1-2

When the front latch is
a diskette. The diskette
Its location is ensured
stop is encountered and
opened, access is provided for
is held in place by plastic
when the diskette is inserted
the eJection mechanism latches.
insertion of
guide rails.
until a back
Closing the front latch activates
resulting in accurate centering and
drive hub is held at a constant speed
D. C. motor. The head(s) remain in
until the front latch is opened.
the cone clamping mechanism,
clamping of the diskette. The
of 300 RPM by a servo-controlled
contact with the recording media
The heads are positioned over the desired track by means of a four-
phase stepper motor/band assembly and its associated electronics.
This positioner uses a one-step rotation to cause a one track linear
movement.
Data recovery
differentiator,
data decoding
electronics include a low-level read amplifier,
zero crossover detector, and digitizing circuits. No
capabilities are provided.
The drive has the following sensors:
1. A Track ° sensor detects when the head/carriage assembly is
positioned at Track O.
2. An index sensor is positioned to generate a digital signal
when an index hole on the diskette is detected. The index
sensor distinguishes index and sector holes in a hard-
sectored diskette.
3. A write protect sensor disables the write electronics when
a write protect tab is applied to the diskette.
4. A motor control switch.
1.5 PHYSICAL DESCRIPTION
A
representative drive is shown in Figure 1-1.
mounted in a vertical or horizontal plane. However,
board must be on the uppermost side when the
horizontally.
The drive can be
the logic circuit
drive is mounted
The spindle is belt driven by aD.
tachometer. The servo control circuit
speed of the spindle.
C.
and
motor with an integral
tachometer control the
The read/write
mounted to a
ferrite/ceramic
hours.
head assembly is positioned by a split band positioner
stepper motor. The read/write heads are glass-bonded,
structures with a life expectancy of 20,000 operating
Operator access for diskette loading is provided via a horizontal slot
located at the front of the drive.
The electronic components of the drive are mounted on two printed
circuit boards. The logic circuit board is mounted above the chassis.
The motorcontrol circuit board is mounted on the bottom of the
chassis. Power and interface signals are routed through connectors
plugging directly into the logic circuit board.
1-3

FIGURE 1-1
D1SK DRIVe
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I

SE:CTION 2
PRODUCT SPECIfICATIONS
INTRODUCTION
This section contains the mechanical, electrical and operational,
reliability, and environmental specifications for the TM50-1 and
TM50-2 drives.
2.1 MECHANICAL SPECIfICATIONS
The physical dimensions of the drive are located in
Figure 2-1.
2.2 ELECTRICAL AND OPERATIONAL SPECIFICATIONS
The electrical and operational specifications are located
in Table 2-1.
2.3 RELIABILITY SPECIFICATIONS
The reliability specifications are located in Table 2-2.
2.4 ENVIRONMENTAL SPECIfICATIONS
The environmental specifications are located in Table 2-3.
TAN DON CORPORATION, CHATSWORTH, CALI fORNIA 91311
2-1
I179[)[)[)
001
REV. A

Ul75
3J2±..D1
o
m 1--
7.53
---_ e:=:======;::;:::::":j __ J
-_ .. _--------
l.e7~
I
J.i2!DI
!.6"f
(41.27MM)
"
~DI
6-32
TAPPED
MOUNTlI'G
HOLES
(2 PlCS
EACH SIDE)
I
1.625
(4'1.27 MM)
- j
•
8_00
."
(203.20 MM)
7.69
(l95.33MM)
VIEW A(PC SA)
NOTES: 1. DIMENSIONS ARE GIVEN IN INCHES. METRIC EQUIVALENTS ARE IN PARENTHESES.
2. TOLERANCE ON ALL DIMENSIONS IS ±0.020 INCH, UNLESS OTHERWISE SPECIFIED.
3.
WEIGHTIS APPROXIMATELY 3POUNDS.
DISK DRIVE OUTLINE DRAWING
TAN DON CORPORATION, CHATSWORTH, CALIfORNIA 91311
17 ':1000-0 0 I
REV. A
2-2

TABLE 2 1
ELECTRICAL
AND OPERATIONAL SPECIfICATIONS
Med ia
Media Life (for reference only)
Tracks Per Inch
Tracks Per Drive
TM50-1
TM50-2
Track Spacing
Head Life
Disk Rotational Speed
Average Rotational Latency
Instantaneous Speed Variation (ISV)
Motor Start Time
Seek Time, track to track
Fast Step Motor (Optional)
Head Settling Time
fast Step Motor (Optional)
Average Track Access Time,
including head settling time
Fast Step Motor (Optional)
Typical Recording Modes
Data Transfer Rate
ANSI-compatible,
5-1/4-inch diskette
4 X 10 6 passes per track
48 TPI, both drives
40 Tracks
80 Tracks
0.529 millimeters,
20.8 milinches
20,000 media contact hours
300 RPM ~ 1.5 percent
100 milliseconds
~ 3 percent
One second, maximum
20 milliseconds
6mi 11 iseconds
20 milliseconds
15 milliseconds
287 millisecorlds
95 milliseconds
FM, MFM, MMfM
250,000 bits per second
double density
TAN DON CORPORATION, CHATSWORTH, CALIfORNIA 91311
2-3
I
179000-001
REV. A

TABLE 2-1 (CONTINUED)
ELECTRICAL
AND OPERATIONAL SPECH'ICATIONS
Flux Reversals Per Inch (FRPI),
inside track
Both models, Side 0
TM50-2, Side 1
Unformatted Recording Capacity
TM50-1
TM50-2
D. C. Voltage and
Current Requirements
+5 volts D. C. Power
+12 volts D. C. Power
Shipment
5,535 FFPI
5,877 FRPI
250 kilobytes per disk
500 kilobytes per disk
+5 volts + 0.25 volt at 800
milliamperes, maximum, with
less than 100 millivolts
peak-to-peak ripple.
+12 volts ~ 0.6 volt, 1.3
amperes, maximum, surge for
50 milliseconds, 800
milliamperes average.
When prepared for shipment by
Tandon, the drive meets the
requirements of NSTA preship-
ment test procedure
Project lAo
TABLE
2-2
RELIABILITY SPECIFICATIONS
Error Rates, exclusive of
external sources, e. g.:
electronics, defective and
contaminated diskettes
Soft Errors (Recoverable)
Hard Errors (Nonrecoverable)
Seek Errors
Mean Time Between Failures
Mean Time To Repair
One in 10
9
bits
One in 1012 bits
One in 10
6
seeks
Cl,OOO hours,
25 percent duty cycle
30 minutes
TANDON CORPORATION, CHATSWORTH, CALIFORNIA 91311
2-4
I
179DDD-001
REV. A

TABLE 2-3
ENVIRONMENTAL SPECIfICATIONS
Temperature
Operating, media dependent
Nonoperating
Relative Humidity
Operating, noncondensing,
media dependent
Nonoperating, noncondensing
Altitude
Operating or Nonoperating
20-to-80 percent
5-to-95 percent
152.4 meters, 500 feet, below sea level,
to 15,240 meters, 50,000 feet, above
sea level
TANVON CORPORATION, CHATSWORTH, CALIfORNIA 91311
2-5
I179VDD
001
REV. A

SECTIUN 3
UPERATION
INTRODUCTION
This section contains information on how to unpack, check out, in-
stall, and operate the TM50-1 and TM50-2 drives.
3.1 UNPACKING THE DRIVE
The drives are shipped in protective containers to minimize the
possibility of damage during shipment. The following list is the
recommended procedure for unpacking the drive.
1.
Place the container
on a
flat work surf ace, top side up.
2. Cut
the
tape that
holds
the tab in the slot on
the front side
of
the
container.
CAUTION
Container may spri ng open when the tape is cut.
3. Remove the drive from its plastic bag.
4. Inspect the drive for possible damage.
5. Notify the carrier immediately if any damage is found.
3.2
6.
Save the shipping container for future use.
PREINSTALLATION CHECKOUT
Before applying power to the drive, the following inspection should
be conducted:
1.
Check to ensure the front latch rotates easily.
should remain in the open position when rotated
counterclockwise (horizontal to front panel).
NOTE
When the latch is moved to an open position,
the head arm raises.
It
fully
2. Remove the cardboard shipping insert, and retain for
future shipment.
3. Ensure the front panel is secure.
3-1

4. Ensu re the dr i ve be 1t is 1n place.
5. Manually rotate the drive hub.
It should rotate freely.
6. Ensure both circuit boards are secure.
7. Ensure the connectors are firmly seated.
3.3
The
When
must
MOUNTING THE DRIVE
drive has been designerl
mounterl horizontally,
be the top side.
to be mounted horizontally or vertically.
the logic circuit board side of the rlrive
Tapped mounting holes are providerl on each side and the bottom of the
drive for attachment to user-supplied mounting brackets (figure 2-11.
When installed in either plane, horizontal or vertical, only two
mounting screws are required to securely hold the drive in place.
Two drives may
3.25-inches high.
for mounting in a
be
A
two
mounted in a single, full-size drive enclosure,
two-hole mounting scheme per drive is recommended
rlrive configuration.
Any mounting scheme in which the drive is part of the structural
integrity of the enclosure is not permitted. Mounting schemes should
allow for adjustable brackets or incorporate resilient members to
accommodate tolerances. In arldition, it is recommended that mounting
schemes inclurle no more than two mounting surfaces.
The
rlrive is manufactured and
testerl with some critical internal
alignments that must be maintained. Hence, it is important that
mounting hardware not introduce significant stress on the chassis.
Dust Cover
The design of an
contamination from
since the drive does
Cooling
enclosure should incorporate a means to prevent
loose items, e. g., dust, lint, and paper chad
not have a dust cover.
Heat dissipation from a
hour, under high load
components have access
cooling allows operation
single drive is normally 15 watts, 51 BTU per
conditions. When the drive is mounted so the
to a free flow of air, normal convection
within the specified temperature range.
When
drive.
forced ai r is
Do not intake
used, air flow must be directed outward from the
air through the drive or ~eads and diskettes.
The use of forced air flow is recommended when two drives are mounted
within a single enclosure.
3-2

3.4
INTERFACE CONNECTIONS
Interface connections tor the TM50-1 and TM50-2 drives are made Vla
a user-supplied, thirty-four pin, flat ribbon connector, 3M Part
Number 3463-0001 or AMP Part Number 583717-5, using contact ParL
Number 1-583616-1 for twisted pair or its equivalent. This
connector mates directly with the circuit board connector at trw
rear of the drive. The D. C. power connector has four pins and is
located at the rear of the drive. The interface description of
the connectors, and the location of each one, is contained in this
section. Interface lines are located In Table 3-1. I). C. power
connector pin assignments arc located in Table 3-2.
The signal wire harness should be of the flat ribbon or twisted pair
type, 26-to-28 gauge conductor, compatible with the connector to be
used. The recommended cable length is ten feet maximum.
TABLE 3-1
DRIVE INTERFACE LINES AND PIN ASSIGNMENTS
Input
Control
Lines:
Controller-To-Disk Drive
Ground Pin
Signal
--
I2 Connector Clamp
34
Spare
5 6 Dri ve Select 3
9
10 Drive Select 0
11 12
Drive Select
1
13
14 Drive
Select
2
15 16 Motor On
17 18
Direction Select
19 20 Step
21 22 Compos i te write Data
23 24 write Enable
31 32
Side Select
Output Control Lines:
Disk
Drive-To-Controller
Ground Pin
Signal
--
7 8 IndeX/Sector
25 26
Track 0
27 28 Write Protect
29 30 Composite Read Data
33 34
Connector Clamp
3-3

Input Control Lines
Drive select Lines
The Drive Select lines provide a means of selecting and deselecting a
drive. These four lines select one of the four drives attached to the
controller.
When the signal logic level is true (low), the drive electronics are
activated, and the drive is conditioned to respond to Step or Read/
Write commands. A Drive Select line must remain stable in the true
(low) state until a Step or Read/write command is completed. When
the si<Jnal line logic level is false (hiCJh), the input control lines
and output status lines are disabled.
The drive address is determined by a select shunt on the logic circuit
board. Drive Select lines 0 through 3 provide a means of daisy
chaining a maximum of four drives to a controller. Only one can be
true (low) at a time. An undefined operation results if two or
more drives are assigned the same address or if two or more Drive
Select lines are in the true (low) state simultaneously.
Motor On
When
this signal
nominal speed of
one second. When
drive decelerates
Drive Select.
is true (low), the drive motor accelerates to its
300 RPM, and stabilizes at this speed in less than
the signal line logic level goes false (high), the
to a stop. This signal is not gated with
Direction Select and Step Lines (Two Lines)
When the drive is selected, a true (low) pulse on the Step line,
with a time duration greater than 200 nanoseconds, initiates the
access motion. The direction of motion is determined by the logic
state of the Direction Select line when a step pulse is issued.
The motion is toward the center of the disk if the Direction Select
line is in the true (low) state. The direction of motion is away from
the center of the disk if the Direction Select line is in the false
(high) state.
To ensu re
stable at
pulse, and
proper positioning,
least 100 nanoseconds
remain true (low) 100
the Direction Select line should be
prior to issuing a corresponding step
nanoseconds after it.
The access motion is initiated on the trailing edge of the step pulse.
The time period between consecutive trailing edges of step pulses
should be at least 20 milliseconds.
3-4