Shugart SA860 User manual

This Document was scanned and
contributed by:
Barry A. Watzman
[Note that an extra section on “jumpers” has been added at the end of
the document. This was not originally in the service manual and was
taken from the OEM manual.]

.:
TABLE OF CONTENTS
TABLE OF CONTENTS i
LIST OF FIGURES. . iii
LIST OF TABLES iii
ABBREVIATIONS MNEMONICS iv
SECTION IINTRODUCTION 1-1
1.1 General Description 1-1
1.2 Specifications Summary 1-1
1. 2.1 Performance Specifications 1-1
1.2.2 Functional Specifications 1-2
1.2.3 Physical Specifications 1-2
1. 2.4 Reliability Specifications ........................................1-3
1.3 Functional Characteristics 1-3
1.3.1 Electronics 1-3
1.3.2 Drive Mechanism 1-3
1.3.3 Positioning Mechanism 1-4
1.3.4 Read/Write Heads 1-4
1.3.5 Recording Formats 1-4
1.4 FunctionalOperations 1-4
1.4.1 Power Sequencing 1-4
1.4.2 Drive Selection 1-4
1.4.3 Motor On 1-4
1.4.4 Track Accessing 1-6
1.4.5 Step Out 1-6
1.4.6 Step In 1-6
1.4.7 Side Selection (SA8600nly) 1-7
1.4.8 Read Operation 1-8
1.4.9 Write Operation 1-9
1.4.10 Sequence of Events 1-10
SECTION II ELECTRICAL INTERFACE 2-1
2.1 Introduction 2-1
2.2 Signal Interface 2-1
2.2.1 Input Lines 2-1
2.2.2 Input Line Termination 2-3
2.2.3 Drive Select 1-4 2-3
2.2.4 Side Select (SA860 Only) 2-3
2.2.5 Direction Select 2-4
2.2.6 Step 2-4
2.2.7 Write Gate 2-4
2.2.8 Write Data 2-4
2.2.9 Motor On (Alternate Input) 2-4
2.2.10 In Use (Alternate Input) 2-4
2.2.11 External Write Current Switch (Alternate Input) 2-4
2.2.12 Output Lines 2-5
2.2.13 Track 00 2-5
2.2.14 Index 2-5
2.2.15 Sector (Hard Sector Only) 2-5
2.2.16 Ready 2-5
2.2.17 Read Data 2-6
2.2.18 Sep Data 2-6
2.2.19 SepClock 2-6
2.2.20 Write Protect 2-6
2.2.21 True Ready 2-6
2.2.22 Disk Change (Optional Output) 2-6
2.2.23 Two Sided (Optional Output) 2-7
2.2.24 Alternate I/O Pins 2-7

TABLE OF CONTENTS (CONT.)
2.3 Power Interface 2-7
2.4 Frame Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
SECTION
III PHYSICAL INTERFACE . . . . . . . . 3-1
3.1
Introduction..... . . . . . . . . . . . . . . . .. ,3-1
3.2 J1/P1 Connector , . . . . . . . . . . . . . . . . 3-1
3.3 J2/P2 Connector 3-2
SECTION IV THEORY OF OPERATIONS , , 4-1
4.1 GeneraIOperations 4-1
4.2 Read/Write Operations 4-1
4.3 Read/Write Head , ' ' 4-3
4.4 Write Circuit Operation 4-4
4.5 Read Circuit Operation 4-5
4.6 Drive Motor Control 4-6
4.7 Track Accessing , , , , . 4-6
4.7.1 Stepping 4-6
4.7.2 Carriage Actuator 4-6
4.7.3 Actuator Control Logic. , , , 4-7
4.7.4 Track Zero Indicator 4-9
SECTION VMAINTENANCE, ,5-1
5.1 Maintenance Equipment 5-1
5.1.1 Alignment Diskette .. ,5-1
5.1.2
SA809 Exerciser ,...................................... 5-1
5.1.3 Special Tools 5-1
5.2 Diagnostic Techniques 5-2
5.2.1 Soft Error Detection and Correction 5-2
5.2.2 Write Errors 5-2
5.2.3 Read Errors 5-2
5.2.4 Seek Errors 5-2
5.3 Trouble-Shooting , , 5-2
5.4 Adjustments 5-5
5.4.1 Side 1Downstop Adjustment (SA860 Only) 5-5
5.4.2 Head Radial Alignment ,. 5-5
5.4.3 Read/Write Head(s) Azimuth Check 5-7
5.4.4 Head Amplitude Check 5-8
5.4.5 Track 00 Detector Assembly 5-8
5.4.6 Track 00 Carriage Limiter 5-8
5.4.7 Index Sector Timing 5-8
5.4.8 Door Lock , , , 5-9·
5.4.9 Ejector/Bail 5-10
5.4.10 Stepper Motor ,5-11
5.5 Removals and Replacements 5-12
5.5.1 Faceplate and Door Knob , , 5-12
5.5.2 Drive Motor Assembly 5-12
5.5.3 Top Plate Assembly 5-12
5.5.4 Spindle Hub Assembly , , , 5-13
5.5.5 PCB Assembly 5-14
5.5.6 Door Lock Assembly .5-14
5.5.7 Side 1Arm Assembly (SA8600nly) ,.......... .5-14
5.5.8 Head and Carriage Assembly 5-14
5.5.9 Clamp Hub Assembly 5-15
5.5.10 Bail Assembly , . . . . . . . . . . . . 5-15
5.5.11 Track 00 Detector 5-15
5.5.12 Index/Sector LED Assembly . 5-15
5.5.13 Index/Sector Detector Assembly . .. 5-16
ii

TABLE OF CONTENTS (CONT.)
5.5.14 Write Protect Detector 5-16
5.5.15 Ejector Assembly 5-16
5.5.16 Door Switch 5-16
5.6 Recommended Incoming Receiving Inspection 5-17
5.6.1 Test Equipment 5-17
5.6.2 Procedure 5-17
SECTION
VI SCHEMATIC DIAGRAMS 6-1
SECTION
VII ILLUSTRATED PARTS CATALOG 7-1
7. 1
Description........................................................ 7-1
7.2 Indented Level 7-1
7.3 Quantity Per Level 7-1
7.4 Recommended Spare Parts Stocking Guide 7-27
LIST OF FIGURES
Figure Title
Page
1-1 SA81O/860 Half-Height Floppy Disk Drive 1-0
1-2
SA810/860 Functional Diagram 1-5
1-3 Track Access Timing,
Standard Seek 1-6
1-4 Track Access Timing, Buffered
Seek 1-7
1-5 Read Initiate Timing 1-7
1-6 Read Signal Timing
(FM Encoding) 1-8
1-7
FM and MFM Code Comparisons 1-9
1-8 Write Initiate Timing 1-9
1-9
SA81O/860 General Control and Data Timing Requirements 1-10
2-1
SA81O/860 Interface Connections 2-2
2-2 Input Line Termination 2-3
2-3 Index Timing 2-5
2-4 Sector Timing 2-5
2-5 DC Power Profile 2-7
3-1 Interface Connectors -Physical Locations 3-1
3-2
J1 Connector Dimensions 3-2
3-3 J2/P2 Connector 3-2
4-1 Byte 4-2
4-2 Basic
Read/Write Head 4-2
4-3 Recorded
Bit 4-2
4-4 Reading a Bit 4-3
4-5 IF and 2F Recording Flux and Pulse Relationship 4-3
4-6 Read/Write Heads 4-4
4-7 Write Circuit Functional Diagram 4-5
4-8 Read Circuit Functional Diagram 4-6
4-9 Drive Motor Control 4-6
4-10 Actuator Control Logic 4-7
4-11 Track
00 4-7
4-12 Track 01 4-8
4-13 Track
02 4-8
iii

4-14
4-15
:) -1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
6-1
6-2
6-3
6-4
6-5
7-1
7-2
7-3
7-4
7-5
7-6
LIST OF FIGURES (CONT.)
Track 03 .. __ __ 4-8
Stepper Timing _ _ __ .. ___ _ 4-9
Write Protect Inoperative _ _ .. __ .... _. _. _ _. . . . . . . . . _. _. __ . . 5-3
Diskette Not Rotating _ _ .. _ _ _ 5-4
Side 1Downstop Adjustment _ _ __ .. _ 5-5
Head Radial Alignment ... .. _ . _. _ .. _ . _ __ _. _ 5-6
Motor Plate Mounting Screws __ .. _. . __ . _. _ .. , _. 5-6
Azimuth Burst Patterns . . _. _. _ _ _ _ _ .. . . . . 5-7
Track 00 Carriage Limiter Clearance . _ __ . _. . . __ . _ _ .. 5-9
Door Lock Solenoid Clearance .. __ __ .. _. _ _ __ _. 5-9
Diskette Stop Clearance __ _ .. _. _. .. _ _. _ .. _. _ .. 5-10
Bail Assembly Adjustment . __ . _ _ . .. . _ __ .5-11
Stepper Motor Adjustment _....... .............................. ..5-11
Drive Motor Assembly _
5-13
Schematic Diagram. PCB 25227 (4 Sheets) 6-3
Schematic Diagram. PCB 25247 (4 Sheets) 6-11
Schematic Diagram.
PCB 25249 (4 Sheets) 6-19
Logic Equivalent PIN 16271. Location U13 '" _. _............... _ _6-27
Logic Equivalent
PIN 51420. Location U14 _ __ _ 6-29
SA810/860 Diskette Drive. Exploded View (3 Sheets) .. _7-2
Top Plate Assembly. Exploded View. . . . . . . . . . . . _ _ 7-8
Actuator Assembly. Exploded View 7-10
PCBP/N25227 _ _ _ 7-12
PCB P/N 25247 . 7-16
PCBP/N25249............ . _ _..... .7-20
LIST OF TABLES
Table Title
Page
2-1 DC Power Requirements. ...................... . 2-6
3-1
Recommended J1 Connectors _ 3-2
5-1 Maintenance Equipment 5-1
6-1 Schematic Diagram Applicability . . . _6-1
7
-1 Part Number to Figure Reference Cross Reference . . . .. .7-24
7-2 Calculated Failure
Rates. . . 7-27
7-3
Spare Parts Stocking Guide _. . . _ __ 7-27
iv

SECTION I
INTRODUCTION
1.1 GENERAL DESCRIPTION
The compact SA810 single-sided and SA860 double-sided half-height 8-inch floppy disk drives offer areliable, low
cost, high performance solution for OEM
data storage applications which require maximum capacity in the smallest
space possible.
The SA81O/860 drives are less than half the height of the Shugart SA801 and SA851 floppy disk
drives,
fit in comfortably with aCRT, require no ac voltage, and offer up to 1.6 megabytes of unformatted capacity.
The SA81O/860 offers the following standard features:
a. Half-height sizing:
2.31 in. (59 mm) high by 8.55 in. (217 mm) wide by 12.00 in. (305 mm) deep
b. Interface and media compatibility with Shugart SA801/851 disk drives
c. Low heat dissipation
d. Fast access time
(3 ms track to track)
e. Quiet operation
f. Low media wear due to low mass head
g. Rapid start dc drive motor--Iess than one revolution (eliminates ac requirements)
h. Phase-Locked
Loop Crystal Referenced Motor Speed Control
i. Media compatible with SA801/851 plus IBM 3740
j. Single or double density
k. 0.8/1.6M Bytes (unformatted capacity)
I. Write protect and programmable door lock for improved data security
m. Internal write current switching
n. TRUE READY alerts the system that
the drive is ready to send or receive data
o. Buffered seek
p. Single or multiple drive dc Motor On control
q. Multiple jumper options
r. Shugart's proprietary Bi-Compliant read/write heads with straddle erase elements
s. Extended reliability
t. Activity light
u. Solid die cast chassis
v. Light weight
w. Inline dc and I/O connectors
The SA81O/860 provides the best solution to the user looking for acompact, low cost, and reliable 8-inch floppy
disk drive.
The SA81O/860 is the most versatile disk drive on the market. This drive is backed by an engineering
department that is recognized as the largest, most experienced group in the entire floppy industry. The SA810/860
is the ultimate solution for small business systems, intelligent terminals, personal computer systems, and program
storage
equipment.
1.2 SPECIFICATIONS SUMMARY
1.2.1 Performance Specifications
Capacity
Unformatted
Per Disk
Per Surface
Per Track
SA810
Single/Double Density
400/800 kbytes
400/800 kbytes
5.2/10.4 kbytes
1-1
SA860
Single/Double Density
0.8/1.6 Mbytes
400/800 kbytes
5.2/10.4 kbytes

IBM Format
(128 byte sectors)
Per Disk
Per Surface
Per Track
Transfer Rate
Latency (average)
Access Time
Track to Track
Settle Time
One Track Seek &Settle
Average (including settle)
Motor Start Time
Worst
Case
Typical
1.2.2 Functional Specifications
Rotational Speed
Recording Density
(inside track)
Flux Density
Track Density
Tracks
Index
Encoding Method
Media Requirements
Soft Sectored
32 Sector Hard Sectored
Alignment Diskette
1.2.3 Physical Specifications
SA810
Single/Double Density
250/500 kbytes
250/500 kbytes
3.3/6.66 kbytes
250/500 kbits/sec
83 ms
3ms
13 ms
16 ms
89 ms
165 ms
120 ms
360 ± 2 rpm
3268/6536 bpi
6536 fei
48 tpi
77
1
FM/MFM
SAlOO/102
SA 1011 103
SA120
SA860
Single/Double Density
500/1000 kbytes
250/500 kbytes
3.3/666 kbytes
250/500 kbits/sec
83 ms
3ms
13 ms
16 ms
89 ms
165 ms
120 ms
360± 2rpm
3408/6816 bpi
6816 fei
48 tpi
154
1
FM/MFM
SA150
SA151
SA122
Environmental Limits
Ambient
Temperature:
Relative Humidity:
Maximum Wet Bulb:
DC Voltage Requirements:
Operating
50° to U5°F (9.9° to 46.lOC)
20% to 80%
85 OF (29.4°C)
Storage
-8° to 122°F (-22.2° to 50°C)
1% to 95%
no condensation
Shipping
-40° to 144°F (-40° to 62.2°C)
1% to 95%
no condensation
+ 24.00 ± 2.4 Vdc @ 1.0 Atyp., 1.7 A max., 100 mV ripple.
+5.00 ± 0.25 Vdc @ 0.7 Atyp., 0.7 A max., 50 mV ripple.
NOTE
If the stepper motor is energized by the controller during the single motor start-up time, the drive
will exceed the + 24 Vdc current specification of 1.7 Amax. Under this condition, the current
specification
is 2.2 Amax.
Mechanical Dimensions
Width =
8.55 in. (217 mm)
Height =2.31 in. (59 mm)
Depth =
12.00 in. (305 mm)
Weight =7lbs
(3 kg)
1-2