RO 3000 SERIES DISK DRIVE
PRODUCT SPECIFICATION
PRO - 00077
Rev. 03
Rodime Europe Ltd,
Nasmyth Road,
Southfield Industrial Estate
GLENROTHES,
Fife, KY6 2SD
SCOTLAND.
This document and the information therein is proprietary to Rodime Europe Ltd. No
part of this information may be duplicated, revealed or disclosed without the
prior written consent of Rodime.
Copyright Rodime Europe Ltd, 19S5
TA3LE OF CONTEr^TS
Paraj^raph Page
l.O SCOPE 1
2.0 RELATED DOCUMENTS 1
3.0 PRODUCT DESCRIPTION 1
3.1 General 1
3.2 Mechanical Assemblies 1
3.3 Disk Hub and Drive Motor 1
3.4 Positioner 2
3.5 Heads and Disks 2
3.6 Electronic Assemblies 2
3.7 Index 3
3.8 Indicator and Fault Codes 3
3.9 Drive Dimensions 3
A.O FUNCTIONAL DESCRIPTION 3
4.1 Recording Parameters."^" 3
4.2 Storage Capacity (UnifSDrmatted) 4
4.3 Storage Capacity (Formatted) 4
4.4 Rotational Parameters 4
4.5 Cylinder Access Time 4/5
4.6 Data Access Time 6
4.7 Illegal Addresses 6
4.8 Weight 6
5.0 RELIABILITY AND SERVICE GOALS 6
5. 1 Drive Life 6
5.2 Mean time Between Failure 6
5.3 Service Goals 6
5.4 Data Reliability 7
5.5 Actuator Reliability 7
6.0 OPERATING ENVIRONMENT 7
6.1 Temperature and Humidity 7
6.2 Shock and Vibration 7/8
6.3 Radio Frequency Interference 8
6.4 Magnetic Field 8
6.5 Altitude 8
6.6 Emitted Acoustic Noise 8
TABLE OF CONTENTS (Cont'd)
Paragraph Page
7.0 NON-OPERATING ENVIRONMENT 8
7.1 Temperature and Humidity 8
7.2 Shock and Vibration 9
8.0 HARDWARE INTERFACE 9
8.1 Drive Mounting and Installation 9
8.2 Electrical Interface 10/11
9.0 POWER INTERFACE 11/12
10.0 DATA INTERFACE 12
10.1 MFM Read Data 12
10. -2 MFM Write Data 12
10*3 Drive Selected 13
10.4 Write Pre-Compensation 13
11.0 CONTROL INTERFACE - Drive Inputs 13
11.1 Drive Select 14
11.2 Head Select 14
11.3 Write Gate 14
11.4 Reduced Write Current 14
11.5 Direction In 14
11.6 Step 15
12.0 CONTROL INTERFACE - Drive Outputs 16
16
16
16
16/17
17
-3.0 DRIVE FUNCTIONS 17
13.1 Power Up/Down 18
13.2 Motor Speed 18
13.3 Restore/Recalibrate 18
4.0 FAULT CODES 19
5.0 SAFETY STANDARDS 19
12.1
Index
12.2
Track 000
12.3
Seek Complete
12.4
Ready
12.5
Write Fault
TABLE OF CONTENTS
Paragraph
TABLES
Table 1
Table 2
Table 3
Table 4
FIGURES
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 6
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Control Interface Jl
Data Interface J2
Power Interface
Head Select Matrix
Mounting Details
Connector and Drive Select pin positions
Jl Connector
J2 Connector
J 3 Connector
Control and Power Bus J2/P1
Data Bus J2/P2
System with 4 Drives
Differential Line Driver
Differential Line Receiver
Control Line Termination
Tri-State Output Driver
Read/Write Data Timing
Step Pulse Timing
Index Timing
Recal ibration Schemes
Page
20
21
22
23
24
25
26
26
26
27
28
2S
30
30
31
31
32
33
34
35
Page 1
RO 3000 DISK DRIVE PRODUCT SPECIFICATION
1.0 S COPE
This document describes the physical and functional characteristics of the
RODIME RO 3000 series 3X" Winchester disk drives. It also specifies
interface, installation and environmental requirements.
2.0 RELATED DOCUMENT
Further detailed information referring to the use of the RO 3000 series disk
drives on a host system is given in the User Manual, USM-00098.
3.0 P RODUCT DESCRIPTION
3 . 1 Genera l
The RO 3000 series disk urives are rsindom access storage devices which
use four 95mm magnetic disks to provide up to 54,50 Megabytes of
unformatted on line capacity.
A servo surface is used in conjunction with a rotary voice-coil
positioner to achieve an average access time of 30msec.
A microprocessor with 4K of program memory is used for several drive
operations and for all positioner control functions. These include
velocity control for all seeks, fault detection and interface.
3.2 Mechanical Assemblies
The drive uses the sealed enclosure principle of Winchester head/disk
technology and provides a minimum contamination environment to maintain
head/media integrity.
An internal filter minimises airborne contaminants within the drive
housing. A breather filter on the drive housing cover reduces the
ingress of contaminants through the bearings of the disk motor by
minimising the pressure drop across them.
3.3 Disk Hub and Drive Motor
The disks are fitted to the hub of a three-phase brushless DC motor
rotating at 3600rpm. Hall-effect devices are used for commutation of
the motor windings and motor speed control. Ferrofluidic and labyrinth
sealc are fitted to the drive motor bearing to prevent contamination.
-Cont'd
Page 2
3.4 Positioner
The positioner consists of a rotatory voice-coil actuator, positioner arms
and magnetic recording heads. The positioner is statically balanced about
the actuator spindle.
Positioning is achieved by means of closed-loop servo control using
information derived from a dedicated servo surface.
On power-down, the actuator is driven to the inner radius and a shipping lock
is automatically applied.
3.5 Recording Heads and Disks
The drive contains four disks with one read/write head per disk
surface. One surface is dedicated to the servo inforir.atior. for the
positioner.
The electrical interface between the recording heads and the
electronics board is by means of a flat flexible circuit cable which
incorporates the pre-amplifier circuits for all of the recording heads.
3.6 Electronic Assemblies
The drive contains one printed circuit board whose functions include:
3.6.1 Read/write and head selection;
3.6.2 Motor speed control;
3.6.3 • Closed-loop positioner controller;
3.6.4 Host controller interface;
3.6.5 Microprocessor, which providest
3.6.5.1 full automatic power up sequence;
3.6.5.2 motor speed control check to -f/- 1% during power up;
3.6.5.3 regular motor speed control checks to 4-10%, -5% after
power-up;
3.6.5.4 control of output lines and latching of fault
conditions;
3.6.5.5 voice-coil positioner control including mode select
and velocity ramp generation;
3.6.5.6 fault codes on front panel LED;
Cont'd...
Page 3
3.0 PRODUCTION DESCRIPTION (Cont'd)
3.7 Index
Index is derived from information recorded on the servo surface once
per revolution of the disk.
3.8 Indicator and Fault Codes
A red LED indicator is provided on the facia and indicates that the
drive is selected and ready. This LED is also used to flash error
codes should certain fault conditions arise in the drive. These codes
are listed in section 14.
3.9 Drive Dimensions
The dimensions of the drive and of the plastic front facia are given in
Figure 1. Also shown are the mounting holes.
4.0 FUNCTIONAL DESCRIPTION
4.1 Recording Parameters
Data is recorded on both sides of the disks (except on the servo disk
which uses only one side for data):
4.1.1 Bit density : 15072 bits per inch (max)
4.1.2 Flux density : 15072 flux changes per
inch (max)
4.1.3 Coding : K.F.K.
4.1.4 Track Density : 1040 tracks per inch (max)
Cont * d . . •
Page 4
4.0 FUNCTIONAL DESCRIPTION (Cont'd)
4.2 Storage Capacity (Unformatted)
4.2.1 Disks per drive
4.2.2 Cylinders
4.2.3 Data tracks per cylinder
4.2.4 Data bytes per track
4.2.5 Data tracks per drive
4.2.6 Capacity (Megabyte$"^
4.3 Storage Capacity (Formatted)
Since the RO 3000 series disk drives are soft-sectored, various format
schemes may be used for stcing data. Here we quote the typical formatted
capacity for the popular choice of 256 bytes per sector.
3055
3045
4
3
872
872
6
5
10,417
10.417
5,232
4,360
54.50
45.42
3055
3045
4.3.1 Data bytes per sector
4.3.2 Data sectors per track
4.3.3 Data bytes per track
4.3.4 Capacity (Megabytes)
4 . 4 Rotational Parameters
Disk rotational speed
Data transfer rate
4.5 Cylinder Access Time
256
256
32
32
8,192
8,192
42.86
35.71
3,600 ♦/- 36rpm
g
5 X 10 bits per second
The cylinder access time is defined as the elapsed time from receipt at
pin 24 of the interface control signal connector housing PI on the
electronics board of the first STEP command of a sequence of one or
more STEP commands to the issue by the drive of SEEK COMPLETE status at
pin 8 of the same connector. Thus, it irrcludes both seek time and
settling time.
Page 5
4.0 FUNCTIONAL DESCRIPTION (Cont'd)
4.5 Cylinder Access Time (Cont'd)
The RO 3000 series disk drives can accept STEP pulses over a range of
rates. They are buffered before being processed and the fin&l step
rate of the actuator depends on the pulse rate. There are two
operating modes with corresponding access times depending on the
interval, P, between successive step pulses.
4.5.1 Ramp Mode: P g 5us to 300us
The access time is dependent upon step rai:e. Figures for P «
30us are quoted below.
4.5.1.1 Single c/lintjfir : 7 ms
4.5.1.2 872 cylinders (P = 30us ) : 62 ms (maximum)
4.5.1.3 Average cylinder access (P = 30us=) : 30 ms
4.5.2 Unra m ped Mode: P = 350us to 15ms
Step rates in this range cause the positioner to seek in an
unraniped mode. Access time in this mode varies with incoming
pulse rate. Figures for P = 3ms, popular on mau^y controllers,
are quoted below.
4.5.2.1 Single cylinder (P = 3ms) : 7 ms'
4.5.2.2 872 cylinders (P - 3ms') : 2520 ms (max)
4.5.2.3 Average cylinder access (P = 3ms) : 875 ms
Note :
1. In the above, average cylinder access is defined as the total
time for all possible cylinder accesses divided by the number
of all possible cylinder accesses.
2. The transition region between ramped and unramped mode occurs
for step intervals P in the approximate range 310 to 340us. In
this range some seeks will be ramped, others unramped. To
guarantee ramped operation P must be less than or equal to
300us as indicated in 4.5.1 above. Similarly, P greater than
or equal to 350us resTilts in unramped mode on all seek
operations.
Cont'd...
Page 6
4.0 FUNCTIONAL DESCRIPTION (Cont'd)
4.6 Data Access Time
The data access time is defined as the cylinder access time plus
rotational latency of the required address.
4.6.1 Average latency : 8.3ms
4.6.2 Average data access time : 38.3 ms
ramp mode
4.6.3 Head switching time : 5us (maximum)
4.7 Illegal Addresses
Each drive will be accompanied by a map indicating the number of bytes
from INDEX which should not be -used by the host. These will be
ider\tified by cylinder, head and byte number. No illegal addresses
will exist in cylinders and 1. This map will be supplied on a label
fixed to the drive as well as on accompanying documentation. The
maximum number of illegal addresses is as follows:
RO 3055 : 35
RO 3045 : 30
4.8 Veight
0.75kg (max. )
5.0 RELIABILITY AND SERVICE GOALS
5.1 Drive Life
The minimum drive service life is 36,000 Power On Hours. The drive is
capable of 10,000 start/stop operations during service life.
^•2 Mean Time Between Failure
The mean time between failure (MTBF) of the RO 3000 series disk drives
shall exceed 20,000 hours*
5.3 Service Goals
No preventative maintenance is required and there are no adjustments on
the drive. The repair that may be effected on-site is replacement of
the electronics board. The mean time to repair (MTTR) including
initial verificafion is 0.5 hours.
5.0 RELIABILITY AND SERVICE GOALS (Cont'd)
5.4 Data Reliability
The drive is responsible for sending differential MFM data to the host
controller where it is stabilised using a phase locked loop (PLL)
circuit and decoded to NRZ data. A meucimum MFM timing Jitter is
specified at the data bus connector housing P2. Note that the maximum
allowed data window for MFM coding at 2.&0MHz is
100 nanoseconds (+/- 50ns).
5.4.1 MFM timing error : +/- 30ns (maximum)
10
(Note: • A soft error rate of less than 1 error in 10 bits read should
result if the PLL/decode timing error on the host corttroller does not
exceed +/- 8 nanoseconds.)
5.5 Actuator Reliability
A seek error occurs when the actuator moves to an incorrect cylinder.
This occurrence shall not exceed 1 seek error in 5 x 10 seeks.
6.0 OPERATING ENVIRONMENT (In system or free standing)
6.1 Temperature and Humidity
Temperature range : 10®C to 50®C
Relative Humidity range : 10% RH to 85% RH
(No condensation)
Maximum wet bulb temperature : 26*0
Maximum rate of change of temperature : IC'C per hour
6.2 Shock and Vibration
The drive shall meet its specified performance while subjected to the
following shock and vibration conditions injected through the mounting
in any of three mutually perpendicular axes. Vibrations are sinusoidal
and shocks half-cycle sinusoidal wave-forms.
Cont ' d . . •
Page 8
6.0 OPERATING ENVIRONMENT (Cont'd)
6.2 Shock and Vibration (Cont'd)
6.2.1 Vibration
Ig pk acceleration, sinusoidal vibration 5-500Hz,
1 octave /minute sweep rate maximun of 2 complete cycles without
interruption.
6.2.2 Shock
lOg pk accln in axis perpendicular to P.C.B.
6g pk accln in two axes parallel to P.C.B.
Duration less than 10msec, half cycle sinusoidal waveform max 2
per second. Maximum 500 shocks, within afly formatted period
and max of 2E9 bits transferred.
6.3 Radio Frequency Interferent-e
Electric field shall not exceed ? volts/r.eter r.m.s. in the range
1.5H2 to lOGHz.
6.4 Magnetic Field
There shall be no source of constant magnetic field which yields more
than 0.0002 Tesla measured in the location occupied by the magnetic
heads when the drive is installed.
6.5 Altitude
Altitude relative to sea level
6.6 Emitted Acoustic Noise
Peak emitted noise
♦6,000 feet, -1.000 feet
50dbA (continuous, maximum)
at 1 metre from the nearest
point on the drive.
7.0 NON-OPERATING ENVIRONMENT
7.1 Temperature and Humidity
Temperature range
Relative humidity range
(No condensation)
Maximum wet bulb temperature
Maximum rate of change of temporatjre
-40*0 to ♦70«C
5% RH to 90% RH
SO'C
ao^C per hour
Page 9
7.0 NON-OPERATING ENVIRONMENT (Cont'd)
7.2 Shock and Vibration
7.2.1 Packed
The approved Rodime shipping container shall protect the drive
against damage when the container is subjected to shock and
vibration in accordance with ASTM, recommended practice for
performance testing of shipping containers. Reference the
following:
ASTMD775 Test method for drop test for loaded boxes.
ASTMD999 Methods for vibration testing of shipping containers
7.2.2 Unpacked
7.2.2.1 Vibration : 2g pk acceleration, sinusoidal
vibration S-SOOHz, 1 oct/min sweep
rate. Max of 4 complete cycles without
interruption.
7.2.2.2 Shock : 50g pk acceleration of maximur^ duration
10msec. Half cycle sinusoidal
waveform. Kaximurri frequency 1 per
10 seconds. Maximum 5 shocks within
any formatted period.
8.0 HARDWARE INTERFACE
8. 1 Drive Mounting and Installation
The RO 3000 series disk drives may be mounted in a host system in any
orientation. The shipping lock effectively locks the actuator during
shipment and releases on application of 12V.
When installing the drive into an enclosure, the breather holes on the
drive top cover must not be obstructed. At least 0.1 inch clearance
must be provided between the top cover and the host frame.
There must be at least 0.1 inch clearance between the drive housing and
the host frame to ensure functional vibration isolation.
The drive may be mounted in either a vertical or horizontal
orientation. It is supplied complete with antivibration mounts and
threaded mounting brackets. See Figure 1.
8.0 HARDWARE INTERFACE (Cont'd)
8.2 Electrical Interface
The electrical interface between the RO 3000 series disk drives and the
host system consists of three connectors:
Connector Jl : Control
Connector J2 : Data
Connector J3 : DC power (+5V, +12V)
The position of these connectors on the drive is shown in Figure 2.
The pin assignments for the interface lines for control (Jl), data (J2)
and power (J3) are given in Tables 1, 2 and 3 respectively.
8.2.1 Control : Connector Jl/Pl
Control signals for the drive are provided via a 34 pin edge
connector (Pl/Jl). The pins are numbered 1 through 34 with the
even pins located on the component side of the board. Pin 2 is
located on the end of the board connector farthest from the DC
power connector and is labelled. A key slot is provided
between pins 4 and 6. The recommended mating connector is AMP
ribbon connector A/N 88373-3. Jl connector dimensions are
given in Figure 3 and pin connections in Figure 6.
8.2.2 Data ; Connector J2/P2
Radial connection of read/write data signals is provided via a
20 pin edge connector (P2/J2). The pins are numbered 1 through
20 with the even pins located on the component side of the
board. The recommended mating connector is AMP ribbon
connector A/N 88373-6. J2 connector dimensions are given in
Figure 4 and pin connections in Figure 7.
8.2.3 Power ; Connector J3/P3
DC power is provided via a 4 pin AMP Mate-N-Lok connector
(P3/J3) P/N 350211-1 mounted via the solder side of the board.
The recommended mating connector is AMP P/N 1-480424-0
utilising AMP pins P/N 350078-4, J3 connector dimensions are
given in Figure 5 and pin connections in Figure 6.
Cont'd...
Pnge 1 1
8.0 HAR DWARE INTERFACE (Cont'd)
8.2 Electrical Interface (Cont'd)
8.2.4 Cabling
It is recommended that the control and data, interface signals
should be carried by flat ribbon or twisted pair cable of
maximum length 20 feet. The power cables should likewise be
twisted pairs of each line voltage and return. See Figure 6.
8.2.5 Multiple Drive Configuration
Up to four RO 3000 series disk drives r.ay be connected to any
host system. Each drive is provided with 4 pairs of pins to
select the drive for drives numbering fror\ 1 to 4. The
position of these pins on Lhe drive is shown in Figure 2. The
pair of pins # 1 corresponding to "DRIVE SELECT 1" is at the
furthest from the interface connector PI. A drive is selected
by shorting the relevant pair of pins with the jumper provided
When connecting more than one drive to a host, the control
lines may be 'daisy-chained' but the data lines require to be
radially (individually) connected. The typical system
configuration is shown in Figure 8. Each drive is provided
with a removable resistor terminator pack for the control
interface (Jl) lines and this pack must be removed from all
except the last drive in the chain. (See Figures 2 and 11).
9.0 POWER INTERFACE : J3
The RO 3000 series disk drives require DC power only. The voltages are
specified at connector J3 on the drive.
Current Current
Maximum Typical
(DC) (Amperes) (Amperes)
♦ 5 (••■/-5X) l.OA 0.7A
^-12 (4./-.5%) 1.5A 0.8A
At power-on, the drive circuitry draws 2.0A max at ♦127.
Cont'd.
Page 1?
9.0 POWER INTERFACE : J3 (Cont'd)
9.1 The 5V rise time must not exceed 1 second.
9.2 The 12V must follow the 5V within 5 seconds if the 5V is applied first.
9.3 When checking the power supplies, the following loads should be used:
For the 12V supply, the power-up current may be measured using a
standard load of 6.8 ohms and the operating current may be measured
using 12 ohms. With a 5.0 ohm resistive load on the 5V supply and the
above loads on the 12V supply, noise and ripple should not exceed lOOmV
peak to peak up to SOOHz and 50mV peak to peak from'. SOOHz to 5MHz.
9.4 In operation, the maximum ,rate of change of the 12V load due to the
disk drive is lA/ms.
9.5 Average power dissipation : 11 watts
10.0 DATA INTERFACE : J2
The RO 3000 series disk drives trainsmit and receive differential data coded
in MFM (modified frequency modulation). Decoding is performed by the host.
10.1 MFM Read Data J2/17,18
Data recovered by reading a pre-recorded track is transmitted to the
host system using an EI A RS-422 standard differential line driver as
shown in Figure 9. This balanced voltage signal will drive up to 20
feet of twisted pair or flat ribbon cable with an impedance
Z = 105 ohms. The recommended receiver is shown in Figure 10. The
transition of "+MFM READ DATA" going more positive than
"-MFM READ DATA" represents a magnetic flux transition on the disk
under the selected head. Timings are shown in Figure 13.
10.2 MFM Write Data J2/13,14
Data for writing on the drive should be transmitted from the host using
an EIA RS-422 standard differential line driver as shown in Figure 9.
The drive receiver is shown in Figure 10. The transition of
"+MFM WRITE DATA" going more positive than "-MFM WRITE DATA" will
result in a flux reversal on the disk under the selected head, provided
"WRITE GATE" is TRUE and the drive is selected. Timings are shown in
Figure 13. It is recommended that "MFM WRITE DATA" be inactive when
"WRITE GATE" is FALSE.
Cont'd. . .
Page 13
10.0 DATA INTERFACE : J2 (Cont'd)
10.3 Drive Selected J2/1
The "DRIVE SELECTED" line is TRUE when the drive is defined as drive N,
using the appropriate drive select switch, and "DRIVE SELECT N" (on Jl)
is TRUE.
10.4 Write Pre-Compensation
During writing, it is required that an advance or delay be applied to
MFM bits when they occur in certain patterns. This compensates for
peak shift on the disk due to pulse crowding. From an analysis of 5
bit sequences, a preferred pre-compensation scheme is shown in 10.4.1
below. Note that LATE or EARLY compensation applies _tQ the centre bit
only of each pattern. No other patterns should be compensated. The
value of compensation should be 10 to 12ns and be appTled on cylinders
650 to 871.
10.4.1
DATA SEQUENCE
LEFTMOST BIT FIRST
00 1
10
00
11
00 1
10
00 1
11
01 1
00
01 1
01
10
00
10
01
10 1
10
10 1
11
11 1
00
11 1
01
REQUIRED
PRE-COMPENSATION OF
CENTRE SIT
EARLY
EARLY
LATE
LATE
EARLY
EARLY
LATE
LATE
LATE
LATE
EARLY
EARLY
11.0 CONTROL INTERFACE
DRIVE INPUTS
Jl
The control bus to the drivo consists of 14 signals, namely 5 inputs, 5
outputs and 4 multiplex control lines for drive select. A removable resistor
pack allows for line termination of all inputs. This is shown in Figure 11.
Note that all signals are low TRUE.
INPUT LOW (TRUE)
INPUT HIGH (FALSE)
OV to *0.8V at -24mA
*5.?'-^V to 3.5V at GA
Cont • d
Page 14
11.0 CONTROL INTERFACE : DRIVE INPUTS : Jl (Cont'd)
11.1 Drive Select (Jl/26, 28. 30, 32 )
These four lines control the multiplexing of the control signals. A
low level on "DRIVE SELECT N" will enable all drives addressed as N
connected to the control bus.
11^2 Head Select (Jl/4. 14, 18 )
These three lines provide for unique selection of each read/write head
(up to 7 m£ucimum) according to the binary coded sequence shown in Table
4. Note that when all "HEAD SELECT" lines are FALSE head will be
selected.
11.3 W rite Gate (Jl/6 )
When TRUE, this line enables data to be written by the drive. When
FALSE, this line enables data to be trsmsferred from the drive to the
host. If "WRITE GATE" is TRUE and a "STEP" pulse is received by the
drive then "WRITE FAULT" is returned by the drive.
11.4 Reduced Write Current (Jl/2 )
This signal is ignored by the drive. Reduced write current switching
is controlled internally by the microprocessor.
11.5 Direction In (Jl/34 )
This signal defines the direction of motion of the read/write head when
the "STEP" line is pulsed. When TRUE, the direction is IN towards the
centre of the disk (increasing cylinder nunber). When FALSE, the
direction is OUT towards the edge of the disk (decreasing cylinder
number).
The "DIRECTION IN" line is sampled when the first step pulse of any
seek is received from the host. Any change thereafter to the direction
line will be ignored by the drive until "SEEK COMPLETE" is TRUE. This
facility allows the drive to be used in an 'overlap seek' mode. Once a
seek has been initiated no attempt should be made to alter the
direction of motion while the "SEEK COMPLETE" line is FALSE.
Cont'd. . .
Page 15
11.0 CONTROL INTERFACE ; DRIVE INPUTS ; Jl (Cont'd)
11.6 Step (Jl/24 )
When used in conjunction with the DIRECTION IN line, the "STEP" signal
enables the read/write heads to be moved. If a command is given which
implies head movement across N cylinders then the "STEP" line must be
pulsed N times. The "STEP" line is active on a high to low transition
(falling edge). The drive has two distinct modes of operation
depending on the pulse rate of the "STEP" line.
1. ramp mode
2. unramped mode
Either mode is automatically selected by the drive by sampling the
pulse rate. In both modes the step pulses are buffered in the drive
before being processed. Step pulse timings are shown in Figure 14.
11.6.1 Ramp mode
If the time between successive step pulses, P, is in the range
5us to 300us, then the drive performs the seek operation by
accelerating and decelerating the read/write heads in
accordance with a defined velocity ramp.
11.6.2 Unramped Mode
If the time between successive pulses, P, is in the range 350us
to 15ms then the drive performs the seek operation by stepping
the read/write heads at a rate derived from the incoming pulse
rate.
If the time between successive pulses, P, is in the range 350us
to 5ms, then SEEK COMPLETE is set after all STEP pulses have ■
been received and after the head settling time.
If the time between successive pulses, P, is in the range 6ms
to 15ms, then SEEK COMPLETE is set after each STEP pulse has
been received and after the head settling time.
If the time between successive pulses, P, is in the range 5ms
to 6ms, then SEEK COMPLETE may sometimes be set after a STEP
pulse, or may be set after all STEP pulses have been received.
Cont'd.. .
12.0 CONTROL INTERFACE ; DRIVE OUTPUTS : Jl
There are 5 output status lines from the drive to the host. These are valid
only **ien the drive is selected. These are driven by a tri-state line driver
as 8ho%m in Figure 12. Outputs are in the high impedance mode of tri-state
logic when the drive is not selected .
OUTPUT LOW (TRUE)
OUTPUT HIGH (FALSE)
OFF STATE OUTPUT CURRENT
12.1 Index (Jl,20)
0.5V (max) at 424mA
2.4V (min) at -3mA
^oxh • ^ozl - 2° "*
This signal makes a transition from TRUE to FALSE (and vice versa) once
for each revolution of the drive motor. The transition is referenced
to a constant point on the rotating disk system. Only the leading edge
of index should be used. The index timing is shown in Figvire 15.
12.2 Track 000 (Jl/10 )
This line is TRUE when the read/write heads are positioned over
cylinder 00.
12.3 Seek Complete (Jl/8 )
This line is TRUE when the read/write heads are settled on the final
cylinder at the end of a seek. Reading or vrriting should not be
attempted when "SEEK COMPLETE" is FALSE. A drive is ready for reading
and writing when "SEEK COMPLETE" and "READY" are TRUE and "WRITE FAULT"
is FALSE. The "SEEK COMPLETE" status is FALSE after 100ns,
approximately, following the leading edge of a step pulses or series of
step pulses. During power up of the drive, "SEEK COMPLETE" is
indeterminate until the auto-calibration sequence is COTiplete and
"TRACK 000" is TRUE. Then "SEEK COMPLETE" goes TRUE.
12.4 Ready (Jl/22 )
This line will be TRUE when the drive is ready to read or write (with
or without an implied seek) and the other output lines are valid.
"READY" will remain TRUE until power off or until "WRITE FAULT" is
TRUE. In the latter case "READY" will remain FALSE until power off.
It cannot be reset via the interface. When FALSE, the drive inhibits
all reading and writing. There are three cases when "READY" is FALSE.
Cont'd. ..
Page 17
12.0 CONTROL INTERFACE : DRIVE OUTPUTS ; Jl (Cont'd)
12.4.1 During power up of the drive the power up sequence results in
"READY" going TRUE, provided:
12.4.1.1 Track zero re-calibration is completed;
12.4.1.2 Motor speed settles to 4/-l% of nominal;
12.4.2 Motor speed worse than approximately +10X or -5% of nominal,
12.4.3 "WRITE FAULT" is TRUE.
12.5 Write fault (Jl/12 )
This line indicates a fault condition in the drive. When TRUE, "READY"
goes FALSE and reading and writing are inhibited in the drive. There
are seven fault conditions which cause "WRITE FAULT" to be TRUE.
12.5.1 Head input line open circuit while "WRITE GATE" TRUE.
12.5.2 Head centre tap open circuit while "WRITE GATE" TRUE.
12.5.3 No write data transitions while "WRITE GATE" TRUE.
12.5.4 No write current in head while "WRITE GATE" TRUE
12.5.5 Step pulse received when "WRITE GATE" is TRUE.
12.5.6 12V supply lower than 10.3V (approx).
12.5.7 5V supply lower than 4.5V (approx).
12.5.8 No servo fields detected.
Note : Only the selected head will be monitored for these faults.
If, after 2 seconds have elapsed, the "WRITE FAULT" condition
no longer exists, the drive will perform the power-up sequence
thus re-calibrating the actuator to track 00. The "READY" will
become TRUE and "WRITE FAULT" will become FALSE. If, however,
the "WRITE FAULT" condition still exists after 2 seconds the
drive will display a fault code (section 14). A power-on reset
should be performed in an attempt to clear the fault condition.
13.0 DRIVE FUNCTIONS
This section describes certain operations performed by the drive which relate
to paur-ticular status lines on the control interface.
Cont'd. . .
Page 18
13.0 DRIVE FUNCTIONS (Cont'd)
13.1 Power up/down
There is no specified power up/down sequence for the RO 810 series disk
drives./ The supplies of 4127 and •i-SV may be applied or removed in any order.
However, if the 5V is applied first, the 12V should follow within 5 seconds.
On power up, the drive will perform an automatic re-calibration sequence
which includes a disk speed check, accurate to 1% of nominal, and a seek to
track 00. The host may use "READY" status to sense the completion of this
sequence. The time until "READY" is TRUE for the RO 810 series disk drive is
12s (max).
Failure of the drive to complete the power-up routine correctly causes
"READY" to remain FALSE.
The drive controller should be powered from the same 5V and 12V supplies as
"the drive. Where this is not possible, the drive controller power supplies
must be within their specified tolerance before power is applied to the
drive. The drive controller power supplies must be removed after power is
removed from the drive.
13.2 Motor Speed
During normal operation the drive automatically monitors motor speed
and causes "READY" to go FALSE AND "WRITE FAULT" to go TRUE if the
speed is worse than +105iJ or -551b, approximately, of nominal. This check
takes a minimum of one disk revolution (16.76ms) and is carried out
when the drive is not seeking.
13.3 Res tore /Recal ibrate
Most hard disk controllers provide a macro command to restore or
recalibrate the drive to Track 00. If the restore/recalibrate command
is carried out as a result of a drive Seek Error, detected by the
controller, then this must be done as a series of single cylinder seeks
checking for TRACK 00 status after every SEEK COMPLETE. (RECAL 1,
Figure 16). Otherwise, the restore/recalibrate command may be carried
out using any step interval in the range 5us to l&ns, with excess STEP
pulses being issued if desired. This scheme is shown in Figure 16
under RECAL 2.
Cont'd...
Page 19
14.0 FAULT CODES
The * Selected and Ready' LED is used to flash error messages should certain
fault conditions arise on the drive. A four bit binsury code is used (long
flash = logical 1, short flash = logical 0) with the most significant bit
occurring first:
e.g. Short, short, long, short = 2 (0010)
Fault Code 1
Fault Code 2
Fault Code 3
(0001)
(0010)
(0011)
Fault Code 4 (0100)
Fault Code 5 (0101)
Fault Codg 6 (0110)
Fault Code 7 (0111)
Fault Code 6 (1000)
Fault Code 9 (1001)
Fault Code 10 (1010)
Fault Code 11 (1011)
No Sync.
No Track Zero.
Motor speed outside -*■/-!% tolerance after
power-up.
Motor speed outside +10%, -5% tolerance in
normal operation.
Seek error.
STEP received while WRITE GATE is TRUE.
WRITE FAULT.
Microprocessor self-test fail (RAM)
Microprocessor self-test fail (ROM)
No INDEX.
Motor not up to speed.
15.0 SAFETY STANDARDS
The Rodime 3000 series disk drives shall comply with relevant product safety
standards such as UL, CSA and FCC.
Page 20
1
1 GND RTN PIN
1 SIGNAL PIN
1
SIGNAL NAME |
i 1
1
2
RESERVED |
1 3
4
HEAD SELECT 2 j
1 5
6
WRITE GATE )
1 7
8
SEEK COMPLETE j
i 9
10
TRACK 00;; 1
1 11
12
WRITE FAULT |
1 13
14
HEAD SELECT j
1 15
16
RESERVED |
(TO J2 PIN 7) 1
1 17
18
HEAD SELECT 1 j
1 19
20
INDEX 1
1 21
22
READY j
1 23
24
STEP 1
1 25
26
DRIVE SELECT 1 j
1 27
28
DRIVE SELECT 2 |
1 29 ;
30
DRIVE SELECT 3 |
j 31
32
DRIVE SELECT 4 |
1 33
34
DIRECTION IN j
TABLE 1
CONTROL INTERFACE Jl
Page 21
i GND RTN PIN
SIGNAL PIN
1
SIGNAL NAME |
1 2
1
DRIVE SELECTED |
1 4
3
RESERVED j
1 6
5
SPARE 1
1 8
7
RESERVED |
(TO Jl PIN 16) (
1 10
9
SPARE 1
1 12
11
GND 1
13
+MFM WRITE DATA |
14
-MFM WRITE DATA |
1 16
15
GND I
17
+MFM READ DATA |
18
-MFM READ DATA |
1 20
19
GND 1
TABLE 2
DATA INTERFACE J2
Page 22
VOLTAGE
PIN 1 : +12 VOLTS DC
PIN 4 : +5 VOLTS DC
GROUND
PIN 2 : +12 VOLTS RETURN
PIN 3 : +5 VOLTS RETURN
TABLE 3 : POWER INTERFACE J 3
Page 23
i HEAD SELECT 1 HEAD SELECTED
1 1 ' 1
1 2 .*! 1 1 1 3065 j 3055 | 3045 1 3025
1 H 1 H 1 H 1 1 i 1
|h|h|l| 111 I ijl
|H|L|H| 2 1 2 j2l 2
1 H 1 L 1 L 1 3 1 3 I 3 1 NHS
I L 1 H 1 H 1 4 1 4 1 4 I NHS
1 L 1 H I L j 5 1 5 1 NHS 1 NHS
j L 1 - L 1 H j 6 1 NHS I NHS 1 N^S
1 L 1 L I L I NHS I NHS j NHS j NHS
NHS = No head selected.
TABLE 4
HEAD SELECT MATRIX
B
DRIVE S
POWER
LINE TERMINATION
RESISTOR PACK
P2 DATA
PI CONTROL
FIGURE 2 : CONNECTOR AND DRIVE SELECT PIN POSITIONS
RpDIA/IE
Page 26
H[ .030 MIN
r
.40
+ .01
.060
+ .003
-i
BOARD THICKNESS'
.062 + .007
J .092+. 005
I
1. 785+. 005
FIGURE 3 : Jl CONNECTOR
.030 MIN
t
.40
+ .01
.060+. 003 *j
BOARD THICKNESS
.062 + .007
J
f
092+.005
Hh
0.04 NOM
.100 NOM
1.085+.005
FIGURE 4 : J2 CONNECTOR
.04 NOM
.100 NOM
f© © © ©"l
FIGURE 5 : J3 CONNECTOR
f?pDI/\/IE
Page 27
Host System
RO 3000
-J Flat Ribbon or Twisted
Pair 20 Ft Max
3
Reserved
2
3
1
>
t
Reserved
4
5
Write Gate
6
7
_ Seek Complete
8
9
• Track 000
10
11
Write Fault
12
13
Head Select
14
15
i
Reserved (to J2 Pin 7)
16
17
Head Select 1
18
19
Index
20
21
r '
Ready-
22
23
^
t
Step
24
- 25
• .
Drive Select 1
26
- i
27
-
Drive Select 2
28
29
Drive Select 3
30
,31
Drive Select 4
32
33
»
Direction In
34
+ 5VDC
Casting
A + 5V Return
^ + 12VDC
A + 12V Return
VJ
DC .
C
;has
sis
A Twisted Pair
Mou
nting Frame
- Jl/Pl
- J3/P3
FIGURE 6
(Isolated from Chassis Ground)
CONTROL AND POWER BUS Jl/Pl
RpDfA/IE
Page 28
Host System
RO 3000
Drive Selected
• 1 2
i
i
<
<
Reserved
3 4
Spare
5 6
•
»
>
Reserved (to Jl Pin 16)
7 8
' Spare
9 10
Ground
11
■
+ KFM Vrjte Data
IZ
13
14
15
- MFM Write Data
Ground
+ MFM Read Data
16
17
18
19
- MFM Read Data
Ground
t
Flat Ribbon or Twisted
Pair 20 Ft Max
20
- J2/P2
FIGURE 7 ; DATA BUS J2/P2
RpDIME
Pa^e 29
Host
Control
Controller
Data
Separator
Drive : 1
DC Voltages
FIGURE 8 : SYSTEM WITH 4 DRIVES
RpDIA/IE
Page 30
FIGURE 9 : RS 422 DIFFERENTIAL LINE DRIVER
-I-
FIGURE 10 : RS 422 DIFFERENTIAL LINE RECEIVER
RpDIA/IE
Page 31
+5V
220 OHMS
330 OHMS
X
OV
FIGURE 11 ; CONTROL LINE TERMINATION
y» 74LS244
FIGURE 12 ■; TRI-STATE OUTPUT DRIVER
Rfi)DIA/IE
Page 32
Drive
Select
A
Head
Select
V
+KFM
Read Data
^ -1
uin
Write
Gate
+MFM
Write Data
*6
-<• ^
Label
Description
Select to Read Data
Write to Read Recovery
Read bit cell
Read Data pulse width
Write Gate true to Write Data
Write Data to Write Gate False
Write bit cell
Write Data pulse width
Mn ZZE
200
25
200
25
Max
Units
5
US
5
us
-
ns
85
ns
400
ns
400
ns
-
ns
-
. ns
FIGURE 13
READ/WRITE DATA TIMING
RpDIA/IE
step
A f
Seek
Complete
Direction
^-IL
'3 f
Page 33
\ f
Label
t^
Description
Vidth of Step pulse
Time between Step pulses
Time from first Step to
Seek Complete False
Direction set to first Step
First Step to direction
change (for overlap seek)
Min
Typ
Max
Units
2.0
5
-
us
5
-
15000
us
40
100
~
ns
^
n<;
150
us
FIGURE 14 : STEP PULSE TIMING
I^DIA/IE
Page 34
Index
J
/
U
t2
Label Descri pti on
Win Typ Max Uni ts
t^ Index pulse width - 175 - us
'2
t^ Index period
16.59 16.76 16.93
ms
FIGURE 15 : INDEX TIMING
l^DIA/E
Page 35
Yes
C
End
3
C
Yes
End
D
FIGURE 16 : RECALIBRATION SCHEMES
