Skip to main content

Full text of "rodime :: Rodime RO3000 Product Specification 1985"

See other formats


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