Control Data BR3B8 User manual

CONTROL DATA
( () fi' PUR A T ION
CONTROL DATA~
8RJ88 DISk STORAG£ UNIT
J
R£F£R£NC£ MANUAL

CONTROL DATA
--~-~~-
j,. I, 1"..... " ~.
CONTROL DATA®
BR:JB8 DISK STORAGE UNIT
REfERENCE
MANUALI .

I
REVISION
RECORD
L
REVISION
DESCRIPTION
A
Manual released.
(9-13-73)
B
Technical and
editorial
changes.
(4-12-74)
C Update manual with Engineering Change Orders PE35350A,
PE35634A. Technical and
(4-7-75) editorial changes.
Changes affect pages 1-3, 1-4, 3-1
3-3
3-
4J 3-6 thru 3-9,
3-12,
3-l3., 3-16, 3-18 thru 3-20,
3-44,
3-45, 3-47.
D
Technical and editorial changes.
Changes affect pl:l:ges 3-78, 3-79/3-80.
(7-25-75)
Publication No.
83301100
© 1973, 1974, 1975
by Control Data Corporation
Printed in the United States of America
ii
Address comments concerning this
manual to:
Control Data corporation
!
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I-~·
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Technical Publications r:epart:nent~'
7801 Catputer Avenue
Minneapolis MN 55435
or use Comment Sheet in the back of
this manual.
83301100 D

PREFACE
This manual has been prepared for customer
engineers and other technical personnel directly
involved with maintaining the disk storage unit
(drive).
Reference information is provided by three sections
in this manual. Section numbers and a brief de-
scription of their contents are listed below:
Section 1 - General Description. Describes equip-
ment functions, specifications, and
equipment number identification.
Section 2 - Operation. Describes and illustrates
the location and use of all controls and
indicators, power on sequencing, and
disk pack installation and removal.
83301100 A
Section 3
indicators, power on sequencing, and
disk pack installation and removal.
Theory of Operation. Describes basic
logic and mechanical functions.
Manuals applicable to the BR3B8 Disk Storage Unit
are as follows:
Publication No.
83301000
83301100
83301200
70629100
Title
Maintenance
Reference
Parts Data
Logic Cards

1. GENERAL DESCRIPTION
Introduction
Assembly Locations
Top Cover Assembly
Deck Assembly
AC Power Supply
Logic Chassis
Equipment Identification
2. OPERATION
Controls and Indicators
Operating Instructions
Power Application
Disk Pack Handling
Disk Pack Installation
Disk Pack Removal
3. THEORY OF' OPERATION
Introduction
Assemblies
Power Supply
AC IDC Distribution
Overtemperature Monitoring
Power On Sequence
Emergency Retract and Data
Protection
Loss of AC Power
Control Interlock Opening
Loss of Speed
Loss of DC Power
Power Off Sequence
Logic Chassis
Deck Assembly
Drive Motor Assembly
Hysteresis Brake Assembly
Spindle Assembly
Actuator
Transducers
Disk Cleaner Assembly
83301100 A
CONTENTS
Blower System
Disk Pack
1-1
1-3
1-3
1-4
1-4
1-4
1-4
Logic Functions
2-1
2-4
2-4
2-4
2-4
2-5
3-1
3-1
3-1
3-1
3-6
3-6
3-7
3-7
3-8
3-9
3-9
3-10
3-10
3-12
3-12
3-12
3-12
3-14
3-18
3-18
Basic Interface Description
Unit Selection
Seek Operations
Servo Circuit
Basic Seek Operation
Short Seeks
Track Servo Circuit
Basic Description
Circuit Description
End of Travel Detection
Cylinder Pulse Generation
First Seek
Direct (Forward/Reverse) Seek
1/0 Sequencing
Positioner Motion
Return to Zero Seek (RTZS)
Machine Clock Circuit
Clock Generation
Index Error Detection
Sector Circuit
Basic Read/Write Principles
Introduction
Writing Data
Reading Data
Track Format
Principles of MFM Recording
Read/Write Operations
Introduction
Head Selection
Write Data Processing
Read Data Processing
3-19
3-19
3-20
3-20
3-29
3-29
3-30
3-34
3-37
3-37
3-37
3-39.
3-42
3-43
3-44
3-48
3-48
3-52
3-53
3-55
3-55
3-57
3-58
3-60
3-60
3-60
3-60
3-60
3-62
3-63
3-63
3-63
3-65
3-70
v

FIGURES
Figure
Page
Figure
Page
1-1
Assembly Locations 1-3
3-24
First Seek Flow Chart 3-45
2-1
Controls and Indicators
2-1
3-25
First Seek Timing Diagram
3-47
3-1
Simplified Logic Symbology
3-2
3-26
Direct Seek Flow Chart
3-49
3-2
Power Distribution
3-3
3-27
Direct Seek Timing Diagram 3-51
3-3 Power Sequencing
3-4
3-28
R TZS Flow Chart
3-54
3-4 Power Interlocks
3-5
3-29 Machine Clock Circuit
3- 56
3-5
Power Off Timing
3-8
3-30
Index Detection Circuit 3-57
3-6 Power Off Sequence
3-11
3-31
Sector Circuit
3-58
3-7
Deck Assembly
3-13
3-32
Sector Circuit Timing Diagram
3-59
3-8 Spindle Assembly
3-14 3-33 Writing Data
3-61
3-9
Actuator Assembly Elements 3-15 3-34 Reading Data
3-61
3-10
Head Loading 3-16
3-35
MFM Recording
3-62
3-11 Head/Arm Assembly Motion 3-17
3-36
Read/Write Chain Block Diagram 3-63
3-12
Speed Detection 3-18
3-37
Head Sector and Write Circuits 3-64
3-13 Velocity Detection 3-19 3-38 Write Data Serializer 3-66
3-14
Blower System 3-20
3-39
Write Serializer Timing 3-67
3-15 Logic Block Diagram 3-21
3-40
Write Irregularity 3-68
3-16
Function Control Timing 3-27 3-41 Peak Shift 3-69
3-17
Status Request Timing 3-29
3-42
Write Compensation Circuit
3-71
3-18
Servo Circuit Simplified Schematic
3-33
3-43
AGC Amplifier Stage (Simplified
3-19 Servo Circuit Simplified Signals 3-35
Logic)
3-72
3-20 Track Servo Disk Layout 3-38 3-44
Data Latch Circuit
3-73
3-21
Track Servo Circuit Simplified
3-45 Phase Lock Oscillator Circuit 3-75
Schematic
3-40
3-46 Data Separator Circuit 3-76
3-22
Track Servo Circuit Simplified
3-47
Read Data Serializer
3-78
Signals
3-41 3-48
Deserializer Timing
3-79
3-23 Cylinder Pulses Generation
3-43
TABLES
Table
Page Table Page
1-1
Drive Specifications
1-1 3-2
Function Control Code Definitions 3-23
2-1 Controls and Indicators
2-2
3-3 Operational Status Byte Definitions
3-28
3-1 I/O Lines
3-22
3-4
Servo Circuit Functions
3-30
vi
83301100 A

SECTION 1
GENERAL DESCRIPTION

INTRODUCTION
The CONTROL DATA® BR3B8 Disk Storage Unit
is a high speed, random access, disk storage device.
The drive is available in both single and dual channel
configurations. Unless otherwise specified, data in
this manual applies to either configuration.
Characteristic
Size
Weight
Temperature
Relative Humidity
(no condensation)
Altitude
AC Power Input
83301100 A
Equipment specifications are listed in Table 1-1.
TABLE 1-1. DRIVE SPECIFICATIONS
Conditions
Specifications
PHYSICAL SPECIFICATIONS
Height
Width
Depth
Operating
Gradient
Non-Operating
Operating
Non-Operating
Operating
Non-Operating
39.5 in. (100 cm)
22 in. (56 cm)
44.5 in. (176 cm)
700 lbs (318 kg)
60
0F
(15. SOC) to gOOF (320C)
120F
(6. 60 C) per hour
-30
0F
(-34
0C)
to +150
oF
(66
0
C)
200/0 to 800/0
5% to 95%
-1000 ft (-305 m) to +10,000 ft (3.05 km)
mean sea level
-1000 ft to +35,000 ft (10.7 km)
POWER SPECIFICA TIO:\'S (Typical Values)
Refer to Pub. No. 83301000 for additional power information.
Definitions: Standby State: dc power on, spindle motor off.
AcceSSing State: pOSitioner continually random seeking.
BR3B8A/C
BR3B8B/D
Phasing (60 Hz)
208v (±10o/a)
60 (±O. 6) Hz, 3rt>
380v (±10o/a)
50 (±0.5) Hz, 3rt>
Two phases supplied from a three-phase delta
source are used per 60 Hz drive. Three-phase
power is available at AITB1 by power cable.
During installation, two phases are connected
to internal power supply. Phases are normally
rotated from drive-to-drive externally so that
each group of three drives present a balanced
three-phase load. Motors are single-phase
connected phase-to-phase.
Phasing (50 Hz)
One phase is used per 50 Hz drive. Three-
phase power available at AITB1 by power cable.
Power is connected phase-to-neutral with
phases rotated externally from drive-to-drive
to present a balanced three-phase load.
1-1

1-2
Characteristics
Current
(208v at 60 Hz)
Power True
(208vat 60 Hz)
Power Factor
(208v at 60 Hz)
Heat Dissipation
(208vat 60 Hz)
Disk Pack
Seek Timing
Latency Time
Recording
Heads
Controller IDrive
Interface Cables
TABLE 1-1. DRIVE SPECIFICATIONS (Cont'd)
Conditions
Standby
Starting
Accessing
Standby
Accessing
Standby
Accessing
Standby
Accessing
Specifications
2 amperes/phase
34 amp/phase for 7 seconds
8 amp/phase
O. 4 kilowatt
1. 2 kilowatt
0,9
0.7
1400 BTU/hr (353 Kg-cal/hr)
4200 BTU/hI" (1060 Kg-cal/hr)
DATA RECORDING SPECIFICATIO)JS
Packs/Drive
Recording Surfaces /
Disk Pack
Usable Tracksl
Recording Surface
Tr~cks/Cylinder
Tracks lInch
Track Spacing
Rotational Speed
Recommended Pack
Access Mechanism
403 Tracks
1 Track
Average
Average
Maximum
Mode
Bit Density
Rate
Quantity
Read/Write Width
Quantity
Maximum Length
Connectors
Pin Assignments
Signal Functions
1
19
411 (404 plus 7 spares)
19
192
0.0052 inch (nominal)
3600 (±20/0) rpm (16.7 ms/rev)
CDC 879
Voice Coil driven by servo loop
55 milliseconds (maximum)
10 milliseconds (ma'{imum)
30 milliseconds
8.33 milliseconds (@ 3600 rpm)
17 milliseconds (@ 3528 rpm)
Modified Frequency :Modulation (:1IF?I)
4040 bpi (inner track nominal)
6. 45 MHz (nominal)
19 recording
1 servo (positioning)
0.0044 in. (nominal)
2 per drive (single channel)
4 per drive (dual channel)
160 ft (48m)
2 per drive (single channel)
4 per drive (dual channel)
Refer to Publication No. 83301000
Refer to Section 3 of this manual
83301100 A

ASSEMBLY LOCATIONS
Figure 1-1 illustrates the major drive assemblies.
Detailed information on the construction and function
of these assemblies is provided in Section 3 of this
manual.
SPINDLE
ASSEMBLY
BLOWER
NOTE S:
&DISK CLEANER ASSEMBLY USED
IN OLDER UNITS.
TOP COVER ASSEMBLY
The top cover assembly protects the drive assem-
blies during customer operations.
The pack cover is opened by means of a latch under
the cover. An electrical switch senses the cover is
opened, and disables spindle motor power.
ACTUATOR ASSEMBLY
SUPPLY
8Y27
Figure 1-1. Assembly Locations
83301100 C
1-3
I
I

DECK ASSEMBLY
The deck assembly has the following major sub-
assemblies:
•
•
•
A spindle assembly to mount the disk pack.
Its associated drive motor runs continuously
whenever a pack is installed, the pack cover
is closed, the START switch is on, and se-
quence power (either from the controller or
with the LOCAL/REMOTE switch on the
power supply in the LOCAL position) are
available.
An actuator assembly that positions the
read/write heads for processing data. The
actuator contains a voice coil positioner
controlled by a closed-loop, continuous-
feedback servo system.
A shroud to surround the disk pack.
The shroud: protects the pack,aids in
directing air from the blower to the
pack, and prevents the operator fran damag-
ing the read/write heads with the pack.
• A read/write chassis to IlOllllt logic cards
that contain logic directly affect-
ing head selection and operation.
• A
timing rrotor and switch assembly in
Sic 09 with PE35634A & Al:x:Ne to delay
head loading for 15 seconds on p:;!WeI'
up sequences to stabilize the speed
of the pack. A disk cleaner ~ly
in sic 09 without PE35634A to clean the
di s ks dur ing p:;!WeI' up sequences.
AC POWER SUPPLY
The ac power supply provides ac power required by
the drive. The ac voltages generated are distributed
to the dc power supply located in the logic chassis
assembly.
The line filter filters the ac power input to the
power supply.
LOGIC CHASSIS
The logic chassis serves as the mounting point for
the main complement of the logic cards and dc power
supply. The chassis is hinge-mounted for easy
1-4
access to the cards (which plug in at the inner side
of the chassis) or to the backpanel terminals (at the
outer side). The baekpanel terminals provide ready
access to all signals entering and leaving each card.
In addition, the cards have test points for monitoring
critical signals within the cards.
The chassis also contains a test point panel
that provides a location for status monitoring of the
de voltages generated by the dc power panel.
Located in the -Wier half of the logic chassis is the
dc power panel. The dc power panel provides dc
power required by t'le drive. It also contains relays
and solid state logic used for power sequencing.
EQUIPMENT IDENTIFICATION
An equipment number is aSSigned to each drive to
identify its configuration. This provides a syste-
matic method of identifying, accounting, and control-
ling changes that aifect drive logic and mechanical
components.
The equipment configuration is identified by a name-
plate attached to the frame at the back of the drive.
The nameplate is visible with the logic chassis open.
The Equipment Identification Number will be similar
to the following:
BR3B8
EqUiPmentT
Identifier
02
Lseries Code
Type Identifier
The Equipment Identifier indicates the basic
function of the unit. This number ,will be
BR3BB on all units for which this series of
manuals have been prepared.
The Type Identifier indicates a non-inter-
changeable difference,in equipments that
affects the interface. The term "Mod" is
sometimes used interchangeably with "Type
Identifier". The following identifiers have
been assigned:
83301100 C

Engineering
Volts/
Channel
Number
Frequency
Configuration
BR3B8A
208/60 Hz
Single
BR3B8B
220/50 Hz
Single
BR3B8C
208/60 Hz
Dual
BR3B8D
220/50 Hz
Dual
The Series Code changes with each non-interchange-
able change within the equipment. Drives with
different series codes are fully interchangeable at
the system level; however, not all of their electrical
or mechanical components may be interchangeable.
Series codes are changed by Engineering Change
Order (ECO) only at the factory.
Other changes are accomplished by Field Change
Order (FCO). These changes may be installed either
at the factory or by field personnel. FCO changes
83301100 A
are indicated by an entry on the FCO Log that accom-
panies each machine. It is important that this log be
kept current by the person installing each FCO.
Unless otherwise specified, all theory. procedures,
and diagrams in these manuals apply to all units.
Exceptions are noted where applicable.
iYlanuals accompanying unit shipments from the man-
ufacturer match the configuration of those units.
Subsequent manual changes are controlled by the
Revision Record sheet behind the title page of every
manual. This sheet identifies the Series Code and
FCO effectivity of manual changes. If maintenance
will be performed using a manual other than the
manual supplied with each drive, verify that the
manual and drive configurations match.
1- 5

SECTION 2
OPERATION

CONTROLS AND INDICATORS
The drive contains several panels and indicators.
Figure 2 ~ 1 locates the panels and indicators on
.TAItT
EEl EEl
UNIT
POWER
OPERATOR CONTROL PANEL
r-T1I-
WIIIITI I
!'1I0UCT
FAUI.T
a cabinet. Table 2 1 describes the various panel
controls and indicators.
LOGIC NUMBER !'LUG
D
TEST POINT PANEL
.. .$ .. S +10 '"'10
@@@@@
DC POWER SUPPLY
8HI
Figure 2 -1. Controls and Indicators
2 -1
83301100 A

Control or Indicator
START switch/indicator
READY indicator
MAINTENANCE indicator
FAULT switch/indicator
TABLE 2-1. CONTROLS AND INDICATORS
Function
Operator Panel
Switch energizes (when pressed to light) spindle drive motor and
begins the First Seek sequence provided the following conditions
are met:
1. Disk pack is in place and canister removed.
2. Pack cover is closed.
3. Circuit breakers are on.
4. Sequence power available either [rom control unit (if power
supply panel LOCAL/REMOTE switch is set to REMOTE)
or from power supply (if power supply LOCAL/REMOTE
switch is set to LOCAL).
Lights when switch is on and conditions 2 and 3 are met. This
allows operator to know which units will sequence on when control
unit sequence power becomes available.
Switch causes a power off sequence when pressed while the indi-
cator is lighted.
The lens of this indicator is blank. Indicator lights when
read/write heads are loaded, a Logic Address Plug is in-
stalled and a Seek Incomplete status is not present.
Lights when related drive has experienced one of the following
conditions:
1. Either ±10v circuit breakers on power supply panel set
to OFF.
2. ON LINE /OFF LINE switch on CE Tester panel set to
OFF LINE.
Lights when one or more of the following unwanted conditions
occur:
1. Read and Write are selected at the same time.
2. More than one head is selected.
3. Voltage fault Low voltage (±5v, ±20v. or -16v). If
-16v is low, heads retract.
4. No servo tracks - Loss of servo track for 200 rns or
more. Heads retract.
5. Write is selected without an On Cylinder signal.
6. Write gate is Q)1 but no write current (current fault>.
,}
2-2 83301100 A

TABLE 2-1. CONTROLS AND INDICATORS (Cont'd)
Control or Indicator
Function
FAULT switch/
7.
Write gate is on dul'ing Index (write over run).
indicator (Cont'd)
8. Write current present without a Write Gate (current fault).
9. Write gate is on but no data transitions for 900 nsec (no
write data).
10. Write gate is on with offset active.
II.
Logic gate temperature has exceeded an acceptable limit.
WRITE
PROTECT
Switch inhibits (when pressed to light) write gate,
preventing drive
switch / indicator
from writing on pack.
LOGIC ADDRESS PLUG
A keyed LAP when installed in this receptacle, assigns a logical
(LAP)
receptacle
address of 0 through 14.
Logic Chassis Test Point Panel
+5, -5, +20, -20,
and Provide a point at which dc voltages in logic chassis can be
GND test jacks
measured (do not use as a voltage source).
AC Power Supply
Elapsed time meter
Active when ac power is applied by UNIT POWER circuit breaker,
Records accumulated drive operating time.
DRIVE MOTOR circuit
Controls application of ac voltage to spindle drive motor.
breaker
+20Y Fuses Protects 20 volt power supply transformer used to derive +20Y
sequence and lamp voltages.
DC
Power Supply
+20Y indicator
Lights to indicate presence of +20Y voltage used by lamps and
power up sequence circuit.
LOCAL/REMOTE switch
Allows power up sequence to be controlled by either the control
unit (when set to REi\IOTE) or by a dc around from power supply
(when set to LOCAL).
±46, ±20,
and ±10 volt
Control application of related dc voltages throughout drive.
circuit breakers
Main Breaker Box
UNIT POWER circuit
Controls application of main ac power.
breaker
83301100 A
2-3