Digital Equipment RK05 Series User manual

Digital Equipment Corporation
Maynard, Massachusetts
RK05 DISK DRIVE
~1AINTENANCE MA~~UAL

RK05
DISK DRIVE
MAINTENANCE MANUAL
DEC-OO-RK05-DA

1st Edition Apri11972
2nd Printing June 1972
3rd Printing October 1972
4th Printing December 1972
Copyright © 1972 by Digital Equipment Corporation
The material in this manual is for information-
al purposes and is subject to change without
notice.
The following are trademarks of Digital Equipment
Corporation, Maynard, Massachusetts:
DEC
FLIP CHIP
DIGITAL
PDP
FOCAL
COMPUTER
LAB

CONTENTS
Page
CHAPTER 1 GENERAL INFORMATION
1.1
Introduction
1-1
1.2
Specifications
1-1
1.3
50/60 Hz Power Option
1-2
1.4 Major Assemblies and Systems
1-3
1.4.1 Controls and Indicators
1-4
1.4.2 Spindle and Drive
1-6
1.4.3 Linear Positioner
1-7
1.4.4 Cartridge Handling System
1-7
1.4.5 Electronic Module
1-9
1.4.6 Air System
1-9
1.4.7
Power Supply
1-9
CHAPTER 2 INSTALLATION
2.1
Unpacking and Inspection
2-1
2.2
Mechanical Installation and Checkout
2-1
2.3
Operation
'''I "'I
,t..-,)
2.3.1 Disk Cartridge Installation and Removal
2-3
2.3.2 Normal Operating Procedure
2-3
CHAPTER 3 INTERFACE
3.1
General
3-1
3.2 Input Interface Lines
3-1
3.2.1
Select (4 Lines)
3-1
3.2.2 Cylinder Address
(8 Lines)
3-1
3.2.3 Strobe
3-1
3.2.4 Head Select
3-2
3.2.5 Write Protect Set
3-3
3.2.6 Write Data and Clock
3-3
3.2.7 Write Gate
3-3
3.2.8 Restore (RTZ)
3-3
3.2.9 Read Gate
3-3
3.3
Output Interface Lines
3-3
3.3.1
File Ready
3-3
3.3.2 R/W/S Ready (Read, Write, or Seek Ready)
3-3
3.3.3 Address Accepted
3-4
3.3.4 Address Invalid 3-4
3.3.5 Seek Incomplete
3-4
3.3.6 Write Protect Status
3-4
3.3.7 Write Check
3-4
3.3.8 Read Data
3-4
3.3.9 Read Clock
3-4
iii

CONTENTS (Conti
Page
3.3.10 Sector Address (4 Lines) 3-4
3.3.11 Sector Pulse 3-5
3.3.12 Index Pulse 3-5
3.3.13 ACLow
3-5
3.3.14 DC Low 3-5
3.3.15 High Density
3-5
CHAPTER 4 THEORY OF OPERATION
4.1 Functional Description 4-1
4.1.1 Start 4-1
4.1.2 Stop
4-1
4.1.3 Track Addressing and Head Positioning 4-2
4.1.4 Read/Write Heads 4-4
4.1.5 Recording Technique 4-7
4.2 Logical Description 4-7
4.2.1 Power
On/Off Sequence 4-7
4.2.2
Start
4-8
4.2.3 Stop
4-11
4.2.3.1 Normal Stop 4-11
4.2.3.2 Low Speed
Stop
4-11
4.2.3.3 AC Low Stop 4-11
4.2.3.4 DC Low Stop 4-12
4.2.4 Disk Drive Addressing 4-12
4.2.5 Seek 4-12
4.2.5.1 Load Heads Seek 4-12
4.2.5.2 Forward Seek 4-13
4.2.5.3 Reverse Seek 4-14
4.2.5.4 Return-to-Zero (Restore) Seek 4-14
4.2.6 Position Servo Logic 4-15
4.2.6.1 Velocity Mode 4-16
4.2.6.2 Velocity Synthesizer 4-17
4.2.6.3 Detent Mode 4-19
4.2.7 Sector/Index Pulse Generation 4-19
4.2.8 Read Operation 4-21
4.2.9 Write Operation 4-23
4.2.10
Fault Detection 4-23
4.2.10.1 Erase Current
Fault
4-24
4.2.10.2 Positioner Lamp Fault 4-24
4.3 Power Supply Description 4-24
CHAPTER 5 MAINTENANCE
5.1 Recommended Tools and Test Equipment
5-1
5.2 Preventive Maintenance
5-1
iv

CONTENTS (Cont)
Page
5.2.1 Elapsed Time Indicator 5-2
5.2.2 500-Hour
PM Procedure 5-3
5.2.3 1,500-Hour
PM Procedure
5-3
5.2.4 3,000-Hour PM Procedure 5-4
5.2.5 Prefilter Removal and Replacement 5-4
5.2.6 Absolute Filter Removal and Replacement 5-4
5.3 Corrective Maintenance
5-5
5.3.1 Linear Positioner
5-5
5.3.Ll
Positioner Removal 5-5
5.3.1.2 Positioner Replacement
5-5
5.3.2 Carriage
5-7
5.3.2.1 Carriage Removal 5-7
5.3.2.2 Carriage Replacement
5-7
5.3.2.3 Carriage Bearing Assembly Removal 5-9
5.3.2.4 Carriage Bearing Assembly Replacement 5-9
5.3.2.5 Transducer Block Removal and Replacement 5-9
5.3.2.6 Servo System Timing Adjustment
5-11
5.3.3 Read/Write Heads 5-14
5.3.3.1 Head Removal 5-14
5.3.3.2 Head Replacement 5-14
5.3.3.3 Read/Write Head Alignment 5-15
5.3.3.4 Read/Write Data Separator (G180 Card) Adjustment 5-16
5.3.4 Spindle 5-18
5.3.4.1 Spindle Removal 5-18
5.3.4.2 Spindle Replacement 5-18
5.3.4.3 Sector Pulse Timing Adjustment 5-18
5.3.5 Spindle Drive Motor 5-20
5.3.5.1 Motor Removal 5-20
5.3.5.2 Motor Replacement 5-20
5.3.6 Drive Belt Removal and Replacement 5-20
5.3.7 Blower Motor
5-21
5.3.7.1 Blower Removal 5-21
5.3.7.2 Blower Replacement 5-22
5.4 Spare Parts List 5-23
5.5 Troubleshooting 5-24
ILLUSTRATIONS
Figure No. Title Page
1-1 Location of Major Assemblies and Systems
1-3
1-2 Controls and Indicators
1-4
1-3
Spindle and Drive System
1-6
1-4
Linear Positioner
1-7
1-5 Cartridge Handling System
1-8
v

ILLUSTRATIONS (ContI
Figure No. Title Page
1-6
Air System
1-9
2-1
Chassis Slide Mounting
2-2
3-1
Controller-to-Disk Drive Interface Lines 3-2
4-1
Functional Block Diagram
4-2
4-2 Start Flow Chart
4-3
4-3 Stop Flow Chart 4-4
4-4 Seek Flow Chart
4-5
4-5
Return-to-Zero (Restore) Flow Chart 4-6
4-6 Head Loading 4-7
4-7 Read/Write Head
4-8
4-8 Simplified Read/Write Head Circuit 4-8
4-9 Double Frequency Pulse Relationship 4-9
4-10 Control and Interlock Block Diagram 4-10
4-11 Linear Position Transducer 4-16
4-12 Velocity Synthesizer Timing 4-18
4-13 Sector/Index Timing 4-20
4-14 Read Timing 4-22
5-1
Prefilter Removal 5-3
5-2 Absolute Filter Removal 5-5
5-3 Top View with Cover Removed 5-6
5-4
Bottom View with Covers Removed 5-6
5-5
Carriage Removal 5-8
5-6 Carriage Bearing Assembly Removal 5-10
5-7 Sine-Cosine Adjustment Waveforms 5-12
5-8 2-Cylinder Seek Waveform 5-13
5-9 64-Cylinder Seek Waveform 5-13
5-10 Position Offset Adjustment Waveform 5-14
5-11 Read/Write Head Adjustments 5-15
5-12 Read/Write Head Alignment Waveforms 5-17
5-13 Spindle Replacement 5-19
5-14 Blower Collar Removal 5-21
5-15 Blower Motor Removal 5-22
TABLES
Table No. Title Page
1-1 Performance Specifications
1-1
1-2
Controls and Indicators
1-4
5-1
Recommended Tools and Test Equipment
5-1
5-2 Preventive Maintenance Schedule 5-2
5-3 Spare Parts List 5-23
vi

RK05 DISK DRIVE

RKOS Disk Drive

CHAPTER 1
GENERAL INFORMATION
1.1 INTRODUClION
The RK05 Disk Drive is a self-contained, random-access, data storage device that is especially well suited for use
in small or medium size computer systems, data acquisition systems, terminals, and other storage applications.
Operational power for this device is provided by a power supply located within the drive cabinet. The RK05 is
manufactured by Digital Equipment Corporation of Maynard, Massachusetts, and can be obtained in four differ-
ent power models.
This compact light weight drive, uses a high density single disk cartridge, similar to the IBM 2315 disk cartridge,
as its storage medium. Two movable heads, which fly above and below the rotating disk surface, can read or re-
cord up to 406 data tracks at 1500 rpm. The double frequency, nonretum-to-zero (NRZ), recording method
used in this drive, can store 24.4 million bits of on-line data. Data formatting is governed entirely by the operat-
ing system.
With the disk select logic contained in each drive, up to four RK05 Disk Drives can be "party-lined" and operated
from a single controller bus.
1.2 SPECIFICATIONS
Table 1-1 lists the performance specifications of the RK05 Disk Drive.
Characteristic
Storage Medium
Type
Disk Diameter
Magnetic Heads
Number
Recording Density and Format
Density
Tracks
Cylinders
Sectors
Table 1-1
Performance Specifications
Specification
Single-disk magnetic cartridge
14 inches
Two
2040 bpi, straddle erase
406 (200 plus 3 spares on each side of the disk)
203 (two tracks each)
4872 (12 per revolution)
(continued on next page)
1-1

Table 1-1 (Cont)
Performance Specifications
Characteristic
Bit Capacities (unformatted)
Per Disk
Per Inch
Per Cylinder
Per Track
Per Sector
Access Times
Disk Rotation
Average Latency
Head Positioning
(including settling time)
Bit Transfer
Transfer Code
Transfer Rate
Electrical Requirements
Voltage
Power
Starting Current
Model Designation
RK05AA
RK05AB
RK05BA
RK05BB
Environment
Ambient Temperature
Relative Humidity
Barometric Pressure
Dimensions and Weight
Width
Depth
Height
Weight
1.3 50/60 Hz POWER OPTION
Specification
24.4 million
2040 (max. at inner track)
120,000
60,000
5,000
1500 ±
30 rpm
20 ms (half rotation)
10 ms -for adjacent tracks
50 ms -average
85 ms -for 200 track movement
Double Frequency, Nonretum-to-Zero Recording
1.44M bits per sec
115/230 Vac @
50/60 Hz
250 VA
Power only: 1.8A
Start spindle: lOA (for 2 sec)
95
to 130 Vac @ 60 ± 0.5 Hz
190 to 260 Vac @ 60 ±0.5 Hz
95 to 130 Vac @ 50 ± 0.5 Hz
190 to 260 Vac@ 50 ± 0.5 Hz
50° to 110°F (67° to 73°F nominal)
8% to 80% (no condensation)
30 ± 3 mm hg
19 in.
26-1/2 in.
10-1/2 in.
110lb
The RK05 Disk Drive is available in the following four power models:
• RK05AA 95 to 130 Vac @ 60 Hz
• RK05AB 190 to 260 Vac @ 60 Hz
• RK05BA 95 to 130 Vac @ 50 Hz
• RK05BB 190 to 260 Vac @ 50 Hz
1-2

Each model is shipped with a complete set of drawings. To change from 50 to 60 Hz operation requires a differ-
ent spindle drive pulley. To change from 115 to 230V operation requires
that the power connector (P2) be re-
configured.
1.4 MAJOR ASSEMBLIES AND SYSTEMS
The RK05 Disk Drive is composed of the following major assemblies and systems:
• Controls and Indicators
• Spindle and Drive System
• Linear Positioner
• Cartridge Handling System
• Electronic Module
• Air System
• Power Supply
Figure
1-1 illustrates the locations, and the subsequent paragraphs describe the functions of each of the majOi
assemblies and systems.
LINEAR
POSITIONER
POWER SUPPLY
ABSOLUTE
AIR FILTER
(UNDERNEATH UNIT}
CARTRIDGE
HANDLING SYSTEM
CARTRIDGE
AIR DUCT
Figure 1-1 Location of Major Assemblies and Systems
1-3
ELECTRONIC
MODULE

1.4.1 Controls and Indicators
The controls and indicators (Figure 1-2) required for normal operation are located on the front
of the drive cab-
inet. Table 1-2 describes the function
of each control or indicator.
Controls and Indicators
ON/OFF
(rocker switch)
RUN/LOAD
(rocker switch)
Figure 1-2 Controls and Indicators
Table 1-2
Controls and Indicators
Description
Placing this switch in the ON position lights the PWR indicator
and applies power to the drive.
Placing this switch in the OFF position,turns off the PWR indi-
cator and removes power from the drive.
Placing this switch in the RUN position (providing all inter-
locks are safe):
a. locks the drive front door
b. accelerates the disk to operating speed
c. loads the read/write heads
d. lights the RUN indicator
Placing this switch in the LOAD position:
a. unloads the read/write heads
b. stops the disk rotation
c. unlocks the drive front door
d. lights the LOAD indicator
CAUTION
Do not switch to the LOAD position during a write op-
eration,
as this results in erroneous data being recorded.
(continued on next page)
1-4

Controls and Indicators
WTPROT
(rocker switch -spring-loaded off)
PWR
(indicator)
RDY
(indicator)
ONCYL
(indicator)
FAULT
(indicator)
WT PROT
(indicator)
LOAD
(indicator)
WT
(indicator)
RD
(indicator)
Table 1-2 (Cont)
Controls and Indicators
Description
Placing this momentary contact switch in the WT PROT posi-
tion lights the
WT PROT indicator and prevents a write opera-
tion
as well as turns off the FAULT indicator, if lit.
Placing this switch in the WT PROT position a second time
turns
off the WT PROT indicator and allows a write operation.
Lights when operating power
is present. Goes off when operat-
ing power
is removed.
Lights when:
a. the disk is rotating at the correct operating speed
b. the heads are loaded
c. no other conditions are present (all interlocks safe) to
prevent a seek, read, or write operation
Goes
off when the RUN/LOAD switch is set to the LOAD po-
sition.
Lights when:
a. the drive is in the Ready condition
b. a seek
or restore operation is not being performed
c. the read/write heads are positioned and settled
Goes
off during a seek or restore operation.
Lights when:
a. erase or write current is present without a WRITE
GATE or,
b. the head position transducer iamp is inoperative.
Goes
off when the WT PROT switch is pressed or when the
drive
is recycled through a RUN/LOAD sequence.
Lights when:
a. the WT PROT switch is pressed or,
b. the operating system sends a Write Protect command.
Goes
off when the WT PROT switch is pressed a second time or
when the drive
is recycled through a RUN/LOAD sequence.
Lights when the read/write heads are fully retracted and the
spindle has stopped rotating.
Goes
off when the RUN/LOAD switch is set to the RUN posi-
tion.
Lights when a write operation occurs. Goes
off when the write
operation terminates.
Lights when a read operation occurs. Goes
off when the read
operation terminates.
1-5

1.4.2 Spindle and Drive
The spindle and drive system (Figure 1-3)
is composed of the spindle, spindle drive motor, and the recording disk.
A
50/60 Hz, single-phase ac motor transfers torque (via the drive belt) to the spindle drive pulley. Belt tension is
maintained by a tension spring anchored to the baseplate.
TENSION SPRING
DRIVE BELT
DRIVE MOTOR
Figure 1-3 Spindle and Drive System
1-6
SPINDLE
SPINDLE
PULLEY

The spindle speed is electronically tested by a circuit that measures the INDEX PULSE interval. When the inter-
val increases to approximately 45 ms, indicating an unsafe speed, the drive is cycled down. If the RUN/LOAD
switch is placed in the LOAD position, ac power is removed from the motor and the spindle coasts to a halt.
1.4.3 Linear Positioner
The linear positioner (Figure 1-1) consists
of the linear motor, the carriage, the read/write heads, and the optical
position transducer. To move the read/write heads across the recording disk, de current
is applied to the bobbin-
wound armature (Figure 1-4)
of the linear motor. The resulting magnetic field reacts with a permanent magnet in
the motor housing to either pull the armature into, or force
it out of, the permanent magnetic field, depending
upon the polarity
of the current applied to the armature. This motion is transferred to the carriage, which is fas-
tened to the armature. As a result, the read/write heads, which are attached to the carriage, move across the sur-
face
of the disk.
DUCKBILL
INSIDE)
CARRiAGE
CARRIAGE SLIDE
Figure 1-4 Linear Positioner
Any carriage movement
is detected by the linear position transducer, which is located on the underside of the car-
riage. The transducer
output is used with the control logic t9 determine the cylinder position of the heads, and
in the servo logic to govern the speed
of the carriage travel.
1.4.4 Cartridge Handling System
The cartridge handling system (Figure I-SA) consists of a cartridge receiver, two receiver lifting cams, and an ac-
cess door opener. During normal operation, the receiver supports the plastic cartridge case, allowing the recording
disk
to rotate freely on the spindle. The rotating spindle drives the disk by magnetic coupling at the disk hub.
1-7

DRIVE MOTOR
DISK CARTRIDGE
SPINDLE
ACCESS DOOR
OPENER
a. Cartridge Removed
,
DRIVE FRONT DOOR
CARTRIDGE
RECEIVER
CARTRIDGE AIR DUCT
CARTRIDGE
ACCESS DOOR
\
~ l \
ACCESS DOOR
OPENER
h. Cartridge Inserted
Figure 1-5 Cartridge Handling System
]-8

As the drive front door is closed, the cartridge is lowered to the operating position and the magnetic coupling
again engages the disk hub. When the cartridge
is in the operating position, the plastic case depresses the
cartridge-on switch and removes the no-cartridge interlock condition.
1.4.5 Electronic Module
The electronic module (Figure 1-1), located
in the right rear portion of the disk drive, holds eight printed circuit
cards. Three
of these cards contain the system logic and the read/write circuits. Two cards contain the position
servo logic. One card
is the cable connector that interfaces the electronics with the positioner and other chassis
mounted components, while the remaining two cards contain the interface cables and terminators.
1.4.6 Air System
The air system (Figure 1-6) consists of the prefilter, blower, absolute filter, plenum chamber, and the cartridge
air duct.
As the blower rotates, unfiltered air is drawn through the prefilter, where it is purged of large dust par-
ticles. The prefiltered air
is then circulated through the electronic module and into the plenum. From here, the
air passes through the absolute filter (where minute contamination
is removed), up the cartridge air duct, and in-
to the disk cartridge. Cooling air from the absolute filter is also shunted, by the plenum, through the linear posi-
tioner. Exhaust air exits through the front grill
of the drive.
LI NEAR POSITIONER
HOUSING
ABSOLUTE
PREFILTER
CARTRIDGE AIR DUCT
CP-0272
Figure 1-6 Air System
1.4.7 Power Supply
The power supply (Figure 1-1), located in the left rear portion of the disk drive, furnishes all the dc voltages for
the drive. The power supply can operate with a 115
or 230V, 50 or 60 Hz line voltage input (Paragraph 4.3).
1-9

CHAPTER 2
INSTALLATION
2.1 UNPACKING AND INSPECTION
The RKOs Disk Drive can be shipped in a rack as an integral part of a system or in a separate container. If the
drive is shipped in a rack, position the rack in the final installation location and unpack it as follows:
1. Remove the shipping brackets from the drive by removing the snap-on bezel beneath the lowest drive.
2. Remove the screws attaching the shipping bracket and latch molding to both sides of the drive.
CAUTION
Do not use the drive front door handle to pull the
drive out from the rack.
3. Slide the drive
out about 3 in. from the rack and pull the shipping brackets out from the sides of the
drive.
Attach the latch molding back onto the drive with the shipping bracket screws.
4. Slide the lowest drive out far enough to gain access to the shipping brackets on the drive directly above
it and remove the screws from these two shipping brackets.
5. Repeat Steps 3 and 4 for each drive in the rack.
6. Remove the drive bottom covers and remove the three rubber shock-mount cushions which isolate the
baseplate from the chassis.
7, Remove the top cover and the spipping bracket from the !i..l1ear positioner.
8. Retain all packing material for possible return shipment and inspect the drive for damage. Report any
damage
to the carrier.
If the drive is shipped in a separate container, use care while unpacking it. Do not drop or subject the drive to
unreasonable impact. Unpack the drive according to the packaging instructions shipped with each drive.
2.2 MECHANICAL INSTALLATION AND CHECKOUT
If the RKOs Disk Drive is to b.e installed in an existing rack, first install the chassis slides in the rack as illustrated
in Figure 2-1,
then mount the disk drive on the chassis slides as follows:
1. If the drive is to be mounted in a rack without sufficient weight to prevent tipping when the drive is
fully extended, install cabinet stabilizers before mounting the drive.
2. Pull the chassis slides out until they lock in the extended position.
3. Slide
the drive onto the chassis slides until it locks.
4. Remove the drive
bottom covers and remove the three rubber cushions that isolate the baseplate from
the chassis.
(continued on next page)
2-1

5. Remove the drive top cover and remove the shipping bracket from the linear positioner.
6. Inspect P2 and the spindle pulley to ensure that the drive is configured properly for the input power to
be used (Paragraph 1.3).
7. Plug the BCllA interface cable into card position 7 or 8 of the electronic module. Ensure that an
M930 terminator card (Dwg. No. RK05-0-2) is in the unused interface card position.
8. Fold the interface cable and route it through the slot just below the prefilter at the rear of the drive
cabinet.
9. While holding the interface cable in position, replace the bottom cover.
10. Plug the power cord into the ac line receptacle.
11. Press the ON/OFF switch
ON and ensure that power is properly applied to the drive.
12. Install a test cartridge on the spindle (Paragraph 2.3.1) and run the appropriate diagnostic tests to en-
sure proper electrical and mechanical drive operation.
BOTTOM
PAN
r
RACK
rr--
---:
1It--
--+r
-f-J
I
L.H.
RAIL -~
14f-- R.H.
1 ,1,
II
I:
RK05
I
10.44 ~
~
o CD ggg~
1'!'
~-.-l
~
...
+ 1.47
~ j
:~
~
II Ii
42 ~ 22
II
I
o CD ggg~
+
+
1 II Ii
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I
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+
3l,T
:1
1
21.22
o CD ggg~
+
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:
ill
[Fj
c ~
lL __
-- -'-
Figure 2-1 Chassis Slide Mounting
2-2
RAIL
CHASSIS
SLIDE
CP-0273