Seagate ST-506 User manual

8T506
PRODUCT
MANUAL
. c5S» seagate

ST506
Product Manual
July 4,1983
36036-001
920 Disc Drive, Scotts Valley, CA 95066-4544, USA
Telephone: [phone] • Telex: 176455SEAGATE SCVL
c559 seagate

Copyright Notice
This manual and all the
material contained in it are copyrighted with
all rights reserved. This manual may not be copied, in whole or in
part,
without written consent of Seagate Technology.
Seagate reservesthe right
to change, without notice, the specifications
contained in this manual.

TABLE OF CONTENTS
SECTION
PAGE
1.0 Introduction .................................................. .
1.1 General Description ........................................ .
1.2 Specification Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
1.2.1 Physical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
1.2.2 Reliability Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
1.2.3 Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
1.2.4 Functional Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
2.0 Functional Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
2.1 General Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
2.2 Read/Write and Control Electronics. . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
2.3 Drive
Mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4
2.4 Air Filtration System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5
2.5 Positioning Mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5
2.6 Read/Write Heads and
Discs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5
3.0 Functional Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
3.1 Power Sequencing .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
3.2 Drive Selection
..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
3.3 Track Accessing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.. 8
3.4 Head Selection ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
3.5 Read Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8
3.6
Write Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8

SECTION PAGE
4.0 Electrical Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
4.1 Control Input Lines .......................................... 14
4.1.1 Reduced Write Current .................................. 14
4.1.2 Write Gate ............................................. 15
4.1.3 Head Select 2°, 2' ....................................... 15
4.1.4 Direction In ............................................ 15
4.1.5 Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.1.6 Drive Select 1-4 ......................................... 17
4.2 Control
Output Lines ........................................ 17
4.2.1 Seek Complete ......................................... 18
4.2.2 Track 0 ................................................ 18
4.2.3 Write Fault ............................................ 18
4.2.4 Index .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
4.2.5 Ready ................................................. 19
4.3 Data Transfer Lines ................................ .I. ........ 19
4.3.1 MFM Wr.ite Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.3.2 MFM Read Data ........................................ 21
4.3.3 Read/Write Timing ...................................... 21
4.4 Drive Selected .............................................. 21
4.5 Customer Options ........................................... 22
4.5.1 Radial Operation Option ................................. 22
4.5.2 "0" (Defeat Recal.) Operation ............................. 22
4.5.3 "H" Half Step Option .................................... 22
4.5.4 Nylon Ground Washer ................................... 22
5.0 Physical Interface .............................................. 24
ii

SECTION PAGE
5.1 J1/P1 Connector-Control Signals .............................. 25
5.2 J2/P2 Connector-Data Signals ................................. 25
5.3 J3/P3 Connector-DC Power ................................... 26
5.4 J10/P10 Frame Ground Connector ............................. 27
6.0 Physical Specifications ......................................... 29
6.1 Mounting Orientation ........................................ 29
6.2
Mounting Holes ............................................. 29
6.3 Physical Dimensions ........................................ 29
7.0 Track Format . ................................................. 32
7.1 Gap 1 ..................................................... 33
7.2 Gap 2 .......... " ......................................... 33
7.3 Gap 3 ..................................................... 33
7.4 Gap 4
...... " .. " .. , ...................................... 34
7.5 Defective Sector Flags ....................................... 34
LIST OF ILLUSTRATIONS
FIGURE PAGE
1.0 Air Filtration System/Head Disc Assembly. . . . . . . . . . . . . . . . . . . . . . . .. 5
2.0 Spindle Hub Air Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
3.0 Positioning Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
4.0 Power Up Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7
5.0 Control Signals ................................................ 11
6.0 Data Signals ................................................ " 12
7.0 Typical Connections, 4 Drive System .............................. 13
iii

FIGURE PAGE
8.0 Control Signals Driver/Receiver Combination ....................... 14
9.0 Step General Timing ............................................ 16
9.1 Slow Seek Step Pulse Timing ................................... 16
9.2 Algorithm Driven Seek ......................................... 16
10.0 Index Timing ................................................. 19
11.0 Data Line Driver/Receiver Combination ........................... 20
12.0 Write Precompensation Patterns ................................ 20
13.0 Read/Write Data Timing ........................................ 21
14.0 Option Shunt Block ........................................... 23
15.0 Interface Connector Physical Locations .......................... 24
16.0 J1 Connector Dimensions ...................................... 25
17.0 J2 Connector Dimensions ...................................... 26
18.0 J3 Connector ................................................. 26
19.0 Mounting, Physical Dimensions ................................. 30
20.0 Overall Physical Dimensions .................................... 31
21.0 Track Format Example ......................................... 32
22.0 "A1" Address Mark Byte ....................................... 33
LIST OF TABLES
TABLE PAGE
I J1/P1 Connector Pin Assignments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9
II J2/P2 Connector Pin Assignments ................................ 10
III J3/P3Connector Pin Assignments ................................ 10
IV DC Power Requirements ............... : ........................ 27
V Motor Start Current Requirements ............................... 28
iv

1.0 Introduction
1.1 General Description:
The ST506
disc drive is a random access storage device utilizing two
non-removable 51/4 inch discs as storage media. Each disc surface
employs one read/write head to service 153 tracks.
Low
cost and unit reliability are achieved through the use of a band
actuator and open loop stepper head positioning mechanism. The
inherent simplicity of mechanical construction and electronic con-
trols allow maintenance free operation throughout the life of the
drive. Both PC Boards are mounted outside the Head Disc Assembly
(HDA), allowing field serviceability.
Mechanical and contamination protection for the heads, actuator,
and
discs is provided by an impact resistant aluminum enclosure. An
integral air recirculating system provides clean air through a 0.3
micron filter. A second port in the filter assembly allows ambient air
pressure equalization
without chance of contamination. A patented
spindle pump assures adequate air
flow and uniform temperature
distribution throughout the head and disc area. Thermal isolation of
the stepper and spindle motor assemblies from the disc enclosure
results in a very low temperature rise within the HDA. This provides
significantly greater off-track margin and the ability to immediately
perform read and write operations after power up with no thermal
stabilization delay.
The ST506 is identical in size and mounting configuration to the in-
dustry standard minifloppy disc drives. They use the same DC
voltages, and no AC power is required.
Key Features:
• Storage Capacity of 6.38 megabytes unformatted,
5.0 megabytes formatted.
• Same physical size and mounting as the minifloppy.
• Same DC voltages as the minifloppy.
• Band actuator and stepper motor head positioning.
• 5.0 megabit/second transfer rate.
• Simple floppy-like interface.
• Same track capacity as a double density 8 inch floppy.
-1-

1.2 Specification Summary
1.2.1 Physical SpecificationsIEnvironmental Limits
Ambient Temperature
Operating:
Non-operating: 40°
to 122°F (4° to 50°C)
-40° to 140°F (-40° to 60°C)
Maximum Temperature Gradient
Operating: 18°F/hour or 10°C/hour
Non-operating: Below condensation
Relative Humidity:
Maximum Wet Bulb:
Maximum elevation
Operating:
Non-operating:
8
to 80% non-condensing
78.8
of (26°C)
10,000 feet
-1,000
to 30,000 feet
Maximum Shock Without Incurring Physical Damage
Operating: 10G's*
Non-operating: 20G's*
*No mechanical damage
wi" occur within these limits.
D.C. Power Requirements
+ 12V ±5%, 1.6A typical, 3.5A (At power on)
+ 5V ±5%, .7A typical, 1.0A (Maximum)
Maximum Ripple: 50mV peak to peak
(12V, 5V)
Mechanical Dimensions
Height:
Width:
Depth:
Weight:
Shipping Weight:
Heat Dissipation
Typical:
Maximum:
3.25 inches
5.75 inches
8.00 inches
4.6 pounds
(2.1 Kg)
9.0 pounds (4.1 Kg)
25 watts
29 watts
Maximum Accoustic Output: 50DBA @ 12" distance
1.2.2 Reliability Specifications
MTBF: 11,000 POH, typical usage
MTTR:
30 minutes
PM: Not required
Component design life: 5 years
-2-

Error Rates
Soft Read Errors*: 1 per 10
10
bits read
Hard Read Errors**: 1 per 10
12
bits read
Seek Errors: 1 per 10
6 seeks
*Recoverable
within 16 retries
**Not recoverable within 16 retries
1.2.3 Performance Specifications
Capacity
Per Drive:
Per Surface:
Per Track:
Access Time
Track To Track
Average*:
Maximum*:
Settling Time:
Formatted
5.0 Megabytes
1.25 Megabytes
8,182 Bytes
205 ms
*Using fast seek (includes settling)
Transfer Rate:
Average Latency: 8.33
ms
1.2.4 Functional Specifications
Rotational Speed:
Recording Density:
Flux Density:
Track Density:
Cylinders: .
Tracks:
Read/Write Heads:
Discs:
·3·
Unformatted
6.38 Megabytes
1.59 Megabytes
10,416 Bytes
3ms
85 ms
15ms ±10%
5.0 Mbits/sec
3,600 RPM ± 1%
7,690 BPI
7,690 FCI
255 TPI
153
612
4
2