Shugart SA400L Minifloppy User manual

SA400L Minifloppy™
Diskette Storage Drive
Shugar
m
2D
I—'

TABLE OF CONTENTS
Page
TABLE OF CONTENTS i
LISTOFHGURES iii
LIST OF TABLES v
ABBREVIATIONS/MNEMONICS v
SECTION! INTRODUCTION M
1.1 General Description l-l
1.2 Specification Summary 1*1
1.2.1 Performance Specifications 1-1
1.2.2 Functional Specifications 1-1
1.2.3 Physical Specifications 1*2
1.2.4 Reliability Specifications 1-2
SECTION II ELECTRICAL INTERFACE 2-1
2.1 General 2-1
2.2 Signal Interface 2-2
2.3 PowerInterface 2-2
2.4 Input/Output Lines 2-2
2.5 FrameGround 2-2
SECTION III PHYSICAL INTERFACE 3-1
3.1 General
3.2 J1/PIConnector ^5
3.3 J2/P2 Connector
3.4 Frame Grounding
SECTION IV THEORY OF OPERATION J
4.1 General Operations
4.2 Head Positioning "2
4.3 Diskette Spindle Drive J o
4.4 Read/Write Head
4.5 Recording Format
4.5.1 General
4.5.2 Byte
4.6 Formats ^ o
4.6.1 Soft Sectored Recording Format
4.6.2 Track Layout 'e
4.6.3 Hard Sectored Recording Format
4.7 Drive Motor Control
4.7.1 Head Load
4.7.2 Single DriveSystem
4.7.3 MultipleDriveSystem
4.8 Index Detector
4.9 Track Zero Indication
4.10 Track Accessing
4.10.1 Stepper Motor "o
4.10.2 StepperControl -«
4.11 Read/Write Operations
4.12 Read/Write Head ,2
4.13 WriteCircuitOperation
4.14 Read Circuit Operation ^
4.15 Write Protect
SECTION V MAINTENANCE l'\
5.1 Maintenance Equipment e ,
5.1.1 AlignmentDiskette
5.1.2 Exerciser
5.1.3 Special Tools

5.2 Diagnostic Techniques 5-1
5.2.1 Introduction 5-1
5.2.2 Soft Error Detection and Conection 5-2
5.2.3 Write Error 5-2
5.2.4 Read Error 5-2
5.2.5 Seek Error 5-2
5.2.6 InterchangeError 5-2
5.3 Removalsand Replacements 5-3
5.3.1 Faceplate 5-3
5.3.2 DriveMotor Assembly 5-3
5.3.3 StepperMotor and Actuator Cam 5-3
5.3.4 Head and Carriage Assembly 5-3
5.3.5 Clamp Hub 5-3
5.3.6 Hub Frame Assembly 5-4
5.3.7 Write Protect Switch 5-5
5.3.8 Index Detector Assembly 5-5
5.3.9 Index LED 5-5
5.3.10 Track Zero Switch 5-5
5.4 Check. Adjustments, and Alignment 5-5
5.4.1 Test Point Locations 5-5
5.4.2 Head Amplitude Check 5-6
5.4.3 Motor Speed Adjustment 5-7
5.4.4 Motor Speed Adjustment (Using aFrequency Counter) 5-7
5.4.5 Track GO SwitchAdjustment 5-7
5.4.6 Carriage Limiter 5-9
5.4.7 Index Timing Adjustment (Soft Sector) 5-9
5.4.8 Index/SectorTiming Adjustment (Hard Sector) 5-10
5.4.9 Head/Radial Alignment 5-10
5.4.10 Write Protect Switch Adjustment 5-12
5.4.11 Read/Write Head Cleaning Procedure 5-12
5.5 Receiving Inspection 5-13
5.5.1 Philosophy 5-13
5.5.2 Procedure 5-13
SECTION VI MAINTENANCE DIAGRAMS 5-1
SECTION VII ILLUSTRATED PARTS CATALOG 7-J
7.1 Description
7.2 Cablesand CableConnections 7-1
7.3 Recommended Spare Parts Stocking Guide 7-1

LIST OF FIGURES
Figure Title Page
1-0 SA400LDrive 1-0
2-1 Interface Connections 2-1
2-2 InterfaceSignal Driver/Receiver 2-3
3-1 InterfaceConnectors - PhysicalLocations 3-1
3-2 J1 Connector Dimensions 3-2
3-3 J2 Connector 3-2
4-1 Functional Diagram 4-1
4-2 Byte (FMEncoding) 4-3
4-3 Recommended Soft SectorSingle Density (Even Boundaries) (FM) 4-3
4-4 MFM Recommended Format. 256 Bytes/16Records Per Track (IBM Type) 4-4
4-5 Recommended Hard Sector FM and MFM Formats 4-5
4-6 Motor Control Functional Diagram 4-6
4-7 Drive Select Functional Diagram 4-6
4-8 Index Detector Logic 4-7
4-9 Index Timing Diagram 4-7
4-10 Track GO Indication Diagram 4-8
4-11 Track (X) Timing Diagram 4-8
4-12 StepperControl Functional Diagram 4-9
4-13 Step TimingDiagram 4-9
4-14 Bit Cell 4-10
4-15 Basic Read/Write Head 4-11
4-16 Recorded Bit 4-11
4-17 Readinga Bit 4-11
4-18 IF and 2FRecordingRux and PulseRelationship 4-12
4-19 Read/Write Head 4-12
4-20 Write Circuit FunctionalDiagram 4-13
4-21 Read Circuit FunctionalDiagram 4-14
4-22 Write ProtectFunctional Diagram 4-14
5-1 HubFrameAdjustment 5-4
5-2 Test Point Locations 5-6
5-3 Motor Speed Adjustment 5-7
5-4 TrackZero Position 5-8
5-5 TrackZero Switch Adjustment 5-8
5-6 Carriage Limiter Clearance 5-9
5-7 IndexDetector Adjustment 5-10
5-8 SA400L Service Position 5-11
5-9 Index Timing 5-11
5-10 Correct Head Radial Alignment 5-12
5-11 Head Radial Alignment 5-12
5-12 Write Protect Switch Adjustment 5-13
6-1 Write Protect Inoperative 5-1
6-2
Diskette Not Rotating 5-2
6-3 Track (X) Indicator Inoperative 5-3
6-4
Drive Not Coming On Line 5-4
6-5
Index Pulse Inoperative 5-5
6-6 Drive PCB Logic Diagram 5-6
6-7 Read/Write Logic Diagram 5-6
6-8
Write Protect Logic Diagram 5-6
6-9
Motor Speed Control Logic Diagram 5-6
6-10
Power Diagram 5-7
6-11 400L (40 Track) Read/Write Schematic Diagram (2sheets) 6-9
7-1 SA400L Exploded View 7-2
7-2 DrivePCB Parts Location (P/N 25210) 7-4
7-3 Track 00 Switch Parts Location 7-7
7-4 Carriage/Head Parts Location 7-8
7-5 Hub Frame Parts Location 7-9
7-6
Head Load Solenoid Parts Location 7-10
ill

LIST OF TABLES
Table Title Page
2-1 DC Power 2-2
7-1 P/N to Figure - Reference 7-11
7-2 Cable and Cable Connections Part Numbers 7-12
7-3 Spare Parts Stocking Guide 7-13
ABBREVIATIONS / MNEMONICS
bp!
Bits per Inch
NHA
Next Higher Assembly
CK
Clock
NRZ
Non-Return to Zero
CRC
Cyclic Redundancy Check
R/W
Read/Write
fcl
Flux Changes per Inch
tpi
Tracks per Inch
FM
Frequency Modulation
TRK Track
ID
Identification
WG OFF Write Gate Off
IFC
illustrated Parts Catalog
WP
Write Protect
MFM
Modified FM
2F
Double Frequency
NHA
Next Higher Assembly
ABOUT THIS MANUAL
While every effort has been made to ensure that the information provided herein is correct, please notify us in the
event ofan error or inconsistency. Write any comments on the form in the back of this manual and send to.
Shugart
Technical Publications. MS 3-14
475 Oakmead Parkway
Sunnyvale. CA 94086
(408) 733 ()l(n)
This manual (P/N 39028-1) supersedes and makes obsolete the previous edition of this manual (P N 39028-0.
dated 5/81).
IV

39028-46
FIGURE 1-0. SA400L DRIVE

SECTION 1
INTRODUCTION
1.1 GENERAL DESCRIPTION
This manual provides depot level maintenance information necessary to maintain, trouble-shoot, and repair the
SA400L Minifloppy diskdrive manufactured by Shugart. Aseparate OEM manual (SA400LOEM
P/N 39019) is
available which describes the installation, interface, and power requirements useful for the applications of the
SA400L.
The SA400L floppy drives have these standard features:
a. Compact size and weight similar to most tape cassette units.
b. Single and double density capability.
c. 125/250 k bytes (unformatted) storage capacity.
d. 125/250 k bits/second transfer rate.
e. Low heat dissipation.
f. Positive media insertion to avoid media
damage.
g. EK^ drive motor (eliminates ac requirements).
h. Proprietary read/write head designed and manufactured byShugart.
i. Write protect circuitry,
j. Activitylight.
1.2 SPECIFICATION SUMMARY
1.2.1 Perfomance Specificatlona
Capacity Single Density Double Density
(in bytes) (FM) (MFM)
Unformatted
Per Disk 125,000 250,000
Formatted (16 Records/Track)
Per Disk 81.920 163,840
Per Track 2,048 4,096
Per Sector 128 256
Formatted (10 Records/Track)
Per Disk 102,400 204,800
Per Track 2,560 5,120
Per Sector 256 512
TransferRate 125 k bits/sec. 250 k bits/sec.
Latency (avg.) 100 ms
Access Time
Track-to-Track 20 ms
Average 286 ms
Settling Time 20 ms
1.2.2 Functional Specifications
RotationalSpeed 300 rpm
Recording Density 2768 bpi (FM) 5536 bpi (MFM)
Flux Density 5536 fci (FM) 5536 fci (MFM)
Track Density 48 tpi
1-1

Media Requirements
SA104 (soft-sectored)
SA105 (16 sectors, hard-sectored)
SA107 (10 sectors, hard-sectored)
Industry standard flexible diskette
Oxide on 0.(X)3 in. (0.08 mm) Myleur
5.25 in. (133.4 mm) square jacket
1.2.3 Physical Speclficadons
Operatiiig Shlppiii9 Storage
Environmental Limits
Ambient Temperature 50® to 115®F —40® to 144®F —8® to 117®F
(10.0® to 46.1®C) (-40® to 62®C) -22® to 47'C)
Relative Humidity 20 to 80% 1 to 95% 1 to 95%
Maximum Wet Bulb 85®F (29.4®C) No Condensation No Condensation
DC Voltage Requirements
+12 V ± 5% @ 1.80 A max
-I- 5 V ± 5% @ 0.70 A max
Mechanical Dimensions (exclusive of front panel)
Width = 5.75 in. (146.1 mm)
Height = 3.25 in. (82.6 m,m)
Depth = 8.25 in. (209.6 mm) Nominal
Weight = 3 lbs. (1.36 kg) Nominal
Power Dissipation
13.3 Watts (45.3 BTU/hr) Continuous (typical)
7.3 Watts (24.9 BTU/hr) Standby (typical)
1.2.4 Reliability Specificatioiis
Mean Time Between Failure: 8000 power on hours at 25% duty cycle
Mean Time to Repair: 30 minutes
Error Rates:
Soft Read Errors: 1 per 10' bits read.
Hard Read Errors: 1 per 10" bits read.
Seek Errors: 1 per 10® seeks
Media Life:
Passes per Track: 3.0 x 10®
Insertions: 30,(X)0+
1-2

SECTION II
ELECTRICAL INTERFACE
2.1 GENERAL
The electrical interfacebetween the SA400L drive and the host system is viatwo connectors. The first connector,
Jl, provides the signal interface (see figure 2-1). The second connector, J2, provides the dc power. Frame
ground is connected vai a faston connector located at the rear of the casting.
DRIVE
HOST SYSTEM
SPARE SIGNAL LINE
Jl
21
SPARE SIGNAL LINE
4
DRIVE SELECT 4^6 , 3
^INDEX/SECTOR
8 , 5
DRIVE SELECT 1^10 ,' 7
DRIVE SELECT 212 1' 9
.11
DRIVE SELECT 3
14
MOTOR ON
^
16
> 1J
DIRECTION SELECT ^
18
•ID
'17
'19
STEP
^20 ,
WRITE DATA
^
22
WRITE GATE
^
24
'41
'23
^ TRACK 00
26
^ WRITE PROTECT
28 ,
'4D
^READ DATA
30
SPARE SIGNAL LINE
32
SPARE SIGNAL LINE
34
•.Jl
»33
+ 5VDC
»•
J2
4
+12VDC
^1
• 3
, 0
n7^
FRAME "=
GROUND
FIGURE 2-1. INTERFACE CONNECTIONS
2-1

2.2 SIGNAL INTERFACE
Connection to J1 is through a 34 pin PCB edge card connector. The pins are numbered 1through 34 with the
even numbered pinson the component sideofthe PCB. The odd numberedpinsare on the non-componentside.
Pin 2 is located on the end of the PCB connector closest to the comer and is labeled 2. A key slot is provided be
tween pins 4 and 6 for optional connector keying.
2.3 POWER INTERFACE
DC power to the drive is via connector P2/J2 which is located on the non-component side of the drive PCB near
the spindle drive motor. The drive uses two voltages. Table 2-1 outlines the voltage and current requirements.
TABLE 2-1. DC POWER
P2
PIN
1
DC VOLTAGE
-I- 12VDC
+ 12 Return
+ 5 Return
+ 5 VDC
TOLERANCE
±0.6 VDC
±0.25 VDC
CURRENT
*1.80 A MAX
0.90 A TYP
0.70 A MAX
0.50 A TYP
MAX
RIPPLE (p to p)
100 mV
50 mV
•THE 12Vdc CURRENT IS COMPOSED OF THREE COMPONENTS; HEAD LOAD CURRENT, DISKETTE
DRIVE MOTOR CURRENT. AND PCB FUNCTIONS. EACH OF THESE COMPONENTS HAS THE
FOLLOWING CONTRIBUTIONTO THE 12 Vdc CURRENT REQUIREMENTS.
1. PCB FUNCTIONS (DRIVE "STANDBY" CURRENT) —0.4A TYP; 0.5 A MAX
2. HEAD LOAD (DRIVE SELECTED) -0.16 A TYP; 0.2 A MAX
3. DRIVE MOTOR: START(FOR 400 ms MAX) —1.0 A TYP; 1.1 A AMX
RUNNING 0.36 A TYP; 1.1 A MAX (MOTOR STALLED)
38028-17
2.4 INPUT/OUTPUT UNES
There are four output lines from the SA400L. The output signals are driven with an open collector output stage
capable of sinking a maximum of 48 mA at a logical zero level or true state with a maximum voltage of 0.4 V
measured atthe driver. When the line driver isa logical oneor false state the driver is off andthe collector cunentis
amaximum of 250 /lA.
There are nine Input lines to the SA400L. See figure 2-2 for the recommended circuit. These input lines have the
following electrical specifications.
True = Logical zero = Vin ± 0.0 V to +0.4 V @ lin = 48 mA (max)
False = Logical one = Vin + 2.5 Vto +5.25 V I® lin = 250/lA (open)
Input Impedance = 150 ohms
2.5 FRAME GROUND
It is important that the drive be frame grounded to the host system ac ground or frame ground. Failure to do so
may result in drive noise susceptibility. Refer to paragraph 3.4 for the procedure.
2-2