Remex RFD4000-A User manual

TECHNICAL MANUAL
DISKETTE DRIVE
MODELS: RFD4000-A RFD2000-A
RFD4001-A RFD2001-A
IMPORTANT INFORMATION
Changes to the equipment which are made between manual
printings are listed in an addendum at the rear of the manual.
As aconvenience, alist of change pages is given as the last
page in the manual. It is recommended that each of these
pages be marked "Refer to Addendum" so that these changes
can be identified.
EX-CELL-0 CORPORATION
Remex
1733 Alton St •P.O. Box C-19533 •Irvine, CA 92713
112670-103A

Copyright °1979 by REMEX, AUnit of Ex-Cell-0
Corporation. Printed in the United States of America.
All rights reserved. This: book or parts thereof may not
be reproduced in any form without permission of the
publishers
.

»A»aAN8$
The following section is part of the Standard Terms and Conditions and covers only the
Warranty. The reader should refer to the complete Standard Terms and Conditions for
the entire sales agreement.
The Seller warrants to the original Buyer only, that the Product, except as to software
and firmware, is free from defects in workmanship and material under normal use and
service. The Seller's obligation under this warranty shall be limited to furnishing a
replacement for, or at the Seller's option repairing any Product or any part or parts
thereof, which provedefectivewithin 90 days* from the date of shipment by the Seller,
provided such Product or such part or parts are returned to the Seller transportation
prepaid.
The Seller warrants, for aperiod of thirty (30) days from the date of shipment by the
Seller to the original Buyer only, that the software and firmware Products are free from
defects in workmanship and material. Seller's obligation under this warranty shall be
limited to correcting any of said defects or replacing the software or firmware. Said
warranty shall be void and of no effect whatsoever in the event that changes or addi-
tions have been made to the software or firmware (or in the event that the software or
firmware product has been adapted by the Buyer) to serve afunction not within the
system specifications of the Seller.
All replacement Products or parts thereof furnished under this warranty will be invoiced
in the usual manner and adjustments will be made after the Product or part thereof
claimed to be defective has been returned to, and inspected at, the Seller's plant.
Replacements shall be furnished under this warranty F.O.B. Buyer's plant, and the
Seller shall not be responsible for installation costs, (For all international transac-
tions, replacement shall be furnished F.O.B. Port of Entry and Buyer is responsible for
all customs and brokerage fees.) The Buyer shall be liable for all freight inspection
and handling costs if such Product or such part or parts do not prove to be defective.
In no event will any claim for labor in removing or replacing adefective Product or
part for incidental or consequential damages be allowed. No warranty is made as to
any Product or part which has not been installed, operated, or maintained in accord-
ance with Seller's instructions or the instructions contained in its operations or main-
tenance manuals, when furnished by the Seller, or which has been subject to misuse,
abuse, accident, or alteration or to improper or negligent use, maintenance, storage,
transportation or handling.
This warranty is in lieu of all other warranties expresses or implied, including any
warranty of merchantability or fitness for aparticular purpose, and the Seller neither
assumes, nor authorizes any person or firm to assume for it, any other or further obliga-
tion or liability in connection with the sales, installation or use of any product.
UNDER NO CIRCUMSTANCES SHALL SELLER OR ANY AFFILIATE OF SELLER HAVE
ANY LIABILITY WHATSOEVER FOR LOSS OF USE OR FOR ANY INDIRECT, INCI-
DENTAL OR CONSEQUENTIAL DAMAGES.
*AII paper tape products are covered under this warranty for aperiod of one year,
excepting punch mechanisms, lamps and fuses which are warranted for aperiod of 90
days. Flexible disk drives are warranted for aperiod of 180 days.

FOR YOUR SAFETY
Before undertaking any maintenance procedure, whether it be aspecific trouble-
shooting or maintenance procedure described herein or an exploratory procedure
aimed at determining whether there has been amalfunction, read the applicable
section of this manual and note carefully the |WAKiHIfM^j JQncj
contained therein.
CAUTION
The equipment described in this manual contains voltages hazardous to human life
and safety and may contain mechanical components capable of inflicting personal
injury. The cautionary and warning notes are included in this manual to alert oper-
ator and maintenance personnel to the electrical and mechanical hazards and thus
prevent personal injury and damage to equipment.

Section
I
1. 1
1. 1. 1
1. 1. 2
1. 1. 3
1. 1. 4
1. 2
1. 3
1. 4
1. 5
1. 6
1..7
1..7. 1
1.,7. 2
1..7. 3
1.,7. 4
1,.7. 5
1,.8
II
1,.1
2.2
1,.3
2.3..1
2 .3..2
2.4
2.5
2.5,,1
2.5,.2
2.5,.3
TABLE OF CONTENTS
Title Page
GENERAL DESCRIPTION 1-1
EQUIPMENT DESCRIPTION 1-1
RFD4000 FEATURES 1-2
RFD4001 FEATURES 1-2
OPTIONS, FACTORY INSTALLED 1-2
OPTIONS, CUSTOMER INSTALLED 1-3
MAINTENANCE EQUIPMENT REQUIRED BUT NOT SUPPLIED. ... 1-3
EQUIPMENT WARRANTY 1-3
SPECIFICATIONS 1-3
DISKETTE 1-5
RECORDING FORMAT 1-5
MAINTENANCE AND RELIABILITY 1-5
DESIGN LIFE 1-5
RECOVERABLE READ ERROR 1-5
NON-RECOVERABLE READ ERROR RATE 1-5
ACCESS POSITIONING ERROR RATE 1-11
INTERCHANGEABILITY 1-11
MODEL NUMBER DESIGNATION 1-11
INSTALLATION AND INTERFACE 2-1
UNPACKING 2-1
MOUNTING 2-1
INITIAL ADJUSTMENTS 2-1
LINE TERMINATOR 2-1
DRIVE SELECT JUMPERS 2-2
POWER AND SYSTEM CONNECTIONS 2-2
DOUBLE DENSITY DESIGN CONSIDERATIONS 2-5
DOUBLE FREQUENCY AND MFM ENCODING COMPARED .... 2-5
IMPLEMENTATION OF MFM 2-6
M2MF FORMAT DESCRIPTION 2-9
112670-103A

TABLE OF CONTENTS
(CONTINUED)
Title Page
OPERATION 3-1
INPUT-OUTPUT SIGNALS 3-1
OPERATOR CONTROLS 3-1
LOADING AND OPERATING INSTRUCTIONS 3-1
POWER UP MODE 3-1
DISKETTE HANDLING 3-4
DISKETTE LOADING/UNLOADING 3-5
DRIVE SELECTION 3-6
TRACK POSITIONING 3-6
SIDE SELECTION 3-6
READ OPERATION 3-6
WRITE OPERATION 3-7
COMPOSITE SEQUENCE 3-8
ERROR DETECTION AND CORRECTION 3-8
Write Error 3-8
Read Error 3-10
Seek Errors .. . 3-10
RFD4001 FEATURES 3-11
DATA SEPARATOR 3-11
SECTOR OUTPUT 3-11
FACTORY INSTALLED OPTIONS. .3-11
CUSTOMER INSTALLED OPTIONS •3-13
SIDE SELECTION UTILIZING DRIVE SELECT
LINES (RFD4000 AND RFD4001 ONLY) 3-13
RADIAL READY 3-13
RADIAL INDEX AND SECTOR .3-17
TWO-SIDED STATUS OUTPUT (RFD4000 AND
RFD4001 ONLY) 3-17
INDEX OUTPUT 3-17
SECTOR OUTPUT 3-17
vi 112670-103A
Section
III
3. 1
3. 2
3. 3
3. 3. 1
3. 3. 2
3. 3. 3
3. 3. 4
3. 3. 5
3. 3. 6
3. 3. 7
3. 3. 8
3. 3. 9
3.,3.,10
3.
3.
3,
.3.
.3.
.3.
,10.1
,10.2
,10.3
3,.4
3,.4.,1
3.4.,2
3..5
3.6
3.6 .1
3.6 .2
3.6 .3
3.6 .4
3.6 .5
3.6 .6

TABLE OF CONTENTS
(CONTINUED)
Section Title Page
3.6.7 DISK CHANGE OPTION 3-18
3.6.8 DRIVE SELECT WITHOUT LOADING HEADS OR ENABLING
STEPPER MOTOR 3-18
3.6.9 DRIVE SELECT AND STEP MOTOR ENABLE WITHOUT
LOADING HEAD 3-18
3.6.10 HEAD LOAD WITHOUT SELECTING DRIVE OR ENABLING
STEP MOTOR 3-18
3.6.11 IN USE ALTERNATE INPUT 3-19
3.6.12 SIDE SELECTION USING DIRECTION SELECT 3-19
3.6.13 DOOR LOCK LATCH 3-19
3.6.14 WRITE PROTECT OPTIONAL USE 3-19
3.6.15 -5 VOLT OPTION 3-20
3.6.16 DATA SEPARATION OPTION SELECT (MODEL RFD4001 ONLY) .3-20
IV THEORY OF OPERATION 4-1
4.1 BLOCK DIAGRAM DESCRIPTION 4-1
4.1.1 DISKETTE DRIVE MECHANISM 4-1
4.1.2 HEAD POSITIONING MECHANISM 4-1
4.1.3 READ/WRITE HEAD 4-1
4.1.4 DRIVE ELECTRONICS 4-3
4.1.5 DIGNAL MNEMONICS 4-4
4.2 FUNCTIONAL DESCRIPTION 4-4
4.2.1 READ CIRCUITS AND DATA SEPARATOR (RFD4001
AND RFD2001) 4-4
4.2.2 WRITE CIRCUITS <4-6
4.2.3 ERASE CIRCUITS 4-8
4.2.4 STEP MOTOR DRIVE CIRCUITS 4-8
4.2.5 INDEX/SECTOR CIRCUITS 4-10
4.2.6 WRITE PROTECT CIRCUIT 4-11
4.2.7 DISK CHANGE CIRCUIT 4-11
4.2.8 TWO-SIDED CIRCUITRY (RFD400X ONLY) 4-12
4.2.9 DRIVE SELECT LOGIC •4-12
11267O-103A vii

TABLE OF CONTENTS
(CONTINUED)
Title Page
SIDE SELECT LOGIC (RFD4000 AND RFD4001 ONLY) .... 4-12
POWER UP RESET 4-13
DOOR CLOSED CIRCUIT 4-13
CUSTOMER INSTALLABLE OPTIONS 4-13
Side Selection Utilizing Drive
Select Lines 4-13
Radial Ready 4-13
Radial Index and Sector 4-14
Two Sided Status Output 4-14
Disk Change Option •.4-14
Drive Select Without Loading Heads or
Enabling Stepper Motor 4-14
Drive Select and Motor Enable Without
Loading Head 4-16
Head Load Without Selecting Drive or
Enabling Step Motor 4-17
In Use Alternate Input 4-17
Side Selection Using Direction Select
(RFD400X ONLY) 4-18
Door Lock Latch 4-18
Write Protect Optional Use 4-19
-5 Volt Option 4-19
Data Separation Option Select (Models
RFD4001 and RFD2001 Only). 4-19
MAINTENANCE 5-1
GENERAL 5-1
MAINTENANCE PROCEDURES 5-1
READ/WRITE HEAD CLEANING 5-2
Read/Write Head Cleaning, RFD400X Only 5-2
Read/Write Head Cleaning, RFD200X Only ...... 5-2
TROUBLESHOOTING 5-4
ELECTRICAL ADJUSTMENTS 5-8
TRACK ALIGNMENT 5-8
TRACK 00 SWITCH AND MECHANICAL STOP ADJUSTMENT ... 5-9
INDEX ALIGNMENT 5-10
WRITE PROTECT ADJUSTMENT 5-11
viii 112670-103A
Section
4..2.,10
4.,2.,11
4..2..12
4..2..13
4..2,.13,.1
4,
4,
4.
4,
4,
.2,
.2,
.2,
.2,
.2,
.13,
.13,
.13,
.13,
.13,
.2
.3
.4
.5
.6
4,.2,.13 .7
4,.2,.13 .8
4,
4.
.2,
.2,
.13
.13
.9
.10
4
4,
4
4
.2
.2
.2
.2
.13
.13
.13
.13
.11
.12
.13
.14
V
5.1
5.2
5.2 .1
5
5
.2
.2
.1.:
.1.;
L
I
5.2 .2
5.3
5.3 .1
5.3 .2
5.3 .3
5.3 .4

TABLE OF CONTENTS
Section
5.3.5
5.3.6
5.4
5.4.1
5.4.2
5.4.3
VI
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
VII
7.1
7.2
7.3
VIII
8.1
Title Page
R16 CROSSOVER DETECTOR INPUT DC BALANCE ADJUSTMENT. .5-12
R27-3/4 CELL ONE-SHOT ADJUSTMENT
(RFD4001 AND RFD2001 ONLY) 5-12
MECHANICAL ADJUSTMENT 5-13
LATCH PLATE/CARRIER ADJUSTMENT 5-13
DISKETTE LOAD ARM ADJUSTMENT 5-13
HEAD PAD CARTRIDGE ASSEMBLY REPLACEMENT
(RFD200X ONLY) 5-15
PARTS REPLACEMENT 6_1 .
GENERAL 6_1
PRINTED CIRCUIT CARD REPLACEMENT 6-2
MOTOR DRIVE BELT REPLACEMENT 6~2
DRIVE MOTOR ASSEMBLY REPLACEMENT 6-2
HUB PULLEY REPLACEMENT 6-3
INDEX L.E.D. ASSEMBLY REPLACEMENT 6-3
TRACK 00 OPTICAL SWITCH REPLACEMENT 6-3
EXPANDING CLUTCH ASSEMBLY REMOVAL 6-4
CARRIER ASSEMBLY REPLACEMENT 6-4
SINGLE-SIDED and TWO-SIDED INDEX SENSOR ASSEMBLIES
REPLACEMENT 6-5
DRIVE HUB REPLACEMENT 6-5
HEAD LOAD SOLENOID REPLACEMENT 6-6
PARTS LIST 7_1
GENERAL 7_1
OPTIONAL KIT OF PARTS 7_1
RECOMMENDED SPARE PARTS 7_1
SCHEMATIC DRAWINGS 8_1
GENERAL 8_1
112670-103A ix

LIST OF ILLUSTRATIONS
Figure Title Page
1-1 RFD4000 Diskette Drive 1-1
1-2 Installation Drawing, Model RFD4000 and RFD4001 1-6
1-3 Storage Element Physical Dimensions 1-7
1-4 IBM Track Format I-8
1-5 Recording Format Using Index Recording 1-9
1-6 ARecording Format for MFM Encoding .1-9
1-7 32-Sector Format 1-1°
1-8 Model Number Designation 1-13/1-14
2-1 Interface Signal Connections 2-3
2-2 Interface Signal and Connector Locations 2-4
2-3 Recommended Interface Circuits 2-4
2-4 Double Frequency Encoding 2-5
2-5 MFM Encoding 2-6
2-6 Basic Components of Double Density System 2-7
2-7 Expected Bit Shift on Read Back Data 2-8
2-8 Precompensated Write Data 2-8
2-9 Data Recovery Timing 2-9
2-10 M2FM Encoding 2-10
3-1 Power Up and Seek Sequence 3-4
3-2 Diskette Insertion 3-5
3-3 Read Sequence Operation 3-7
3-4 Write Sequence 3-8
3-5 General Read and Write Sequences 3-9
3-6 Data Separator Timing 3-12
3-7 32-Sector/lndex Timing •3-12
3-8 Trace and Jumper Locations 3-14
3-9 Trace and Jumper Locations 3-15
4-1 Block Diagram for the RFD4000 and RFD4001 4-2
4-2 Read/Write/Erase Block Diagram •4-5
4-3 Read Circuit and Data Separator Timing Diagram 4-7
4-4 Stepper Motor Energizing Sequence 4-9
4-5 Timing Diagram, Index and Sector Circuits 4-11
4-6 Radial Ready Circuit 4-14
4-7 Radial Index/Sector Circuits 4-15
4-8 Drive Select Without Loading Heads or Enabling
Stepper Motor 4-15
4-9 Drive Select and Motor Enable Without Loading Head 4-16
4-10 Head Load Without Selecting Drive or Enabling
Step Motor 4-17
4-11 Side Selection Using Direction Select 4-18
4-12 Write Protect Optional Use 4-19
x11267O-103A

LIST OF ILLUSTRATIONS (CONTINUED)
Figure Title Page
5-1 TP1 and TP2 Outputs at Track 38 Using The
Alignment Diskette 5-9
5-2 Waveforms -Index/Sector Adjustment 5-11
5-3 3/4 Cell One Shot Adjustment, RFD4001 5-12
5-4 Diskette Load Arm Adjustment 5-14
7-1 Exploded View of RFD4000 7-23/7-24
7-2 Top View, RFD4000 7-25
7-3 Bottom View with P.C. Card Removed 7-26
7-4 Bottom View with P.C. Card 7-27/7-28
8-1 System Schematic, RFD200X 8-3/8-4
8-2 Schematic Drive Card 113971-XXX 8-7/8-8
112670-103A xl

LIST OF TABLES
Table Title Page
1-1 Specifications for the RFD4000 and the RFD4001 1-4
1-2 RFD400X Options 1-12
2-1 Recommended Connectors PI, P4 and P5 2-2
3-1 Interface Signal Descriptions 3-2
3-2 Customer Cut/Add Trace Options 3-16
4-1 Drive Mnemonics 4-20
5-1 Maintenance Equipment Required 5-1
5-2 Inspection and Maintenance Procedures 5-3
5-3 Troubleshooting Chart 5-5
7-1 Recommended Spare Parts List, RFD400X 7-2
7-2 Recommended Spare Parts List, RFD200X 7-3
7-3 Parts List RFD400X/814080-XXX and RFD400X/814090-XXX ... 7-4
7-4 Parts List RFD400X/814255-XXX and RFD400X/814256-XXX ... 7-8
7-5 Parts List RFD200X/814225-XXX and RFD200X/814226-XXX ...7-11
7-6 Parts List RFD200X/814257-XXX and RFD200X/814258-XXX ...7-15
7-7 Miscellaneous and Optional Parts 7-19
7-8 Printed Circuit Card Assembly, Drive, 113971-001, 002. ..7-20
xii 112670-103A

SECTION I
GENERAL DESCRIPTION
1.1 EQUIPMENT DESCRIPTION
The REMEX RFD4000 and RFD4001 Diskette Drives are asmall, portable, double-
headed direct access storage devices which utilize aremovable two-sided
flexible diskette as the storage medium. See Figure 1-1. The mechanism con-
sists of abelt driven spindle, spindle motor, two read/write heads and a
split band stepping motor drive system for positioning the heads. The drive
also uses alight emitting diode and phototransistor for index sensing, and a
printed circuit board to provide all required internal electronic functions.
The RFD4000 and RFD4001 are identical except the RFD4001 provides for data and
clock separation from the data stream. The RFD2000 is identical to the RFD4000
except data is recorded only on one side; similarly the RFD2001 is identical to
the RFD4001 for the same reason. All information given in this manual is
identical to all four drives unless specifically noted.
Magnetic data is written on or read from the diskette surface by one of two
read/write heads which are positioned to concentric tracks on the diskette
surface by means of the stepper motor. The diskette spindle is belt driven
at 360 RPM by adrive motor.
Figure 1-1. RFD4000 Diskette Drive. The RFD4001, RFD2000 and
RFD2001 are Identical in Outward Appearance.
112670-103A 1-1

1.1.1 RFD4000 AND RFD2000 FEATURES
All units provide physical and electrical interface compatibility with the
Shugart SA 850R/851R with the exception of the LOW CURRENT input which is
used on the REMEX drives. The use of the LOW CURRENT input provides improved
data integrity compared to similar models by other manufacturers. The RFD4000
and RFD4001 are media compatible with the single-sided IBM 33FD drives and
two-sided IBM 43FD drives. Read/Write/Erase head geometry is identical to
that in IBM diskette drives and the mechanism for positioning the head meets
the precise requirements of track location, thereby allowing complete diskette
interchangeability. For applications where IBM format compatibility is not a
requirement, storage capacity may be increased by the use of hard-sectored
diskettes or double density encoding. The drive employs specially designed
electronics which allows data capacity of twice that used in single density
recording techniques.
Drive select code circuitry is provided which allows the address code of an
individual drive to be selected by ajumper. Up to four drives may be
connected in parallel. This feature eliminates the unit select decode cir-
cuitry from the host system and makes it possible for the user to change the
drive address without physically removing the drives and interchanging them.
Unit select line features allows bussing of up to four drives on aribbon
cable.
The heads are ceramic and are positioned on alightweight head carriage.
The bottom head is fixed while the top head is mounted on amovable head
load arm which provides less wear and higher overall reliability. Other
features include automatic erase control which eliminates the need for
erase gate electronics in the host system and ahead load indicator, in-
stalled on the front panel, which is lit when the head is loaded.
1.1.2 RFD4001 AND RFD2001 FEATURES
The RFD4001 and RFD2001 contain the same features as described in Section 1.1.1
for the RFD4000 and RFD2000 except for a built in data and sector separator
that provides separate output lines for sector signals when a33 hole media is
used and provides separate output lines for Data and Clock signals. In the
RFD4000 and RFD2000 data and clock signals are contained in the Read Data
output stream.
1.1.3 OPTIONS, FACTORY INSTALLED
The following options are available on all four model drives. Amore complete
description of each option is included in Section 3.5. In addition certain
modifications are available for optional voltages and drive motors. See
Section 1.8 and Table 1-2 which describes how these options are incorporated
into the model number.
a. Modification for 100/115/230 VAC, operation of a
synchronous motor.
1-2 112670-103A

1.1.4 OPTIONS, CUSTOMER INSTALLED
Several options can be implemented by the customer so that the diskette
drives function differently than that described for the standard unit.
Certain traces are added or subtracted and alternate I/O pins are used to
implement these modifications. Ashorting plug (AMP P/N 530153-2) is used
in some cases as the connection. A16-pin programmable shunt is provided
for the eight most commonly used cut trace options. Section 3.6 describes
in detail the various options available, as well as their installation.
Table 3-2 lists the various options, their trace locations and how the cir-
cuit board is factory wired. It should be noted in those options that use
the same traces and/or alternate I/O pins, only one option can be installed.
1.2 MAINTENANCE EQUIPMENT REQUIRED BUT NOT SUPPLIED
The maintenance procedures in Section 5require equipment that is not supplied.
This equipment is listed in Table 5-1.
1.3 EQUIPMENT WARRANTY
Astatement covering the warranty of this equipment is given on page iii
(second page in book). It should be read and understood. All preventive main-
tenance procedures must be performed as outlined in Section 5.2 during the
warranty period in order that the warranty remain in effect. Any question
arising concerning the warranty should be directed to the REMEX Service Depart-
ment.
1.4 SPECIFICATIONS
The specifications for the four diskette drives are listed in Table 1-1.
112670-103A 1-3

Table 1-1. Specifications for the RFD4000, RFD4001, RFD2000 and RFD2001.
Characteristic Specification
Capacity/Side 400K Bytes, single density, unformatted
800K Bytes, double density, unformatted
250K Bytes, IBM Format (26 sectors), single density
500K Bytes, IBM Format (26 sectors), double density
Recording Density RFD400X: 3408 BPI, single density; 6816 BPI, double density.
RFD200X: 3268 BPI, single density; 6536 BPI, double density.
Track Density 48 TPI
Number of Tracks 154 (77 each side)
Heads 2(EFD4000, RFD4001) ;1(RFD2000, RFD2001) .
Recording Method 2
FM, single density; MFM or MFM, double density
Rotational Speed 360 RPM
Transfer Rate 250K Bits/Sec, single density; 500K Bits/Sec, double density
Latency 83 ms, average
Access Time 3ms, track to track; 15 ms, settle; 91 ms average
(including settling)
.
Head Load Time 35 ms
Motor Start Time 2sec
Media IBM Diskette 1(one side operation only), 2, 2D.
Error Rate y Read Error Rate (Recoverable): Less than 1in 10 bits read.
Read Error Rate (Non-Recoverable): Less than 1in 10 bits read.
Seek Error Rate: Less than 1in 10^ seek operations.
MTBF 6000 power on hours
MTTR 30 minutes
Design Life 15,000 power on hours or 5years
Media Life 3.5 x10 passes/track
A. C. Power See Table 1-2. Current requirement for 100/115 VAC is 0.8A and for 220VAC is 0.4A.
B.C. Power +24 Vdc ±10% @0.6A, typical
+5 Vdc ±5% @1.0A, typical
-7 to -16 Vdc @0.1A typical
Optional -5 Vdc ±5% @0.05A typical
Temperature 40°F to 115°F, Operating
-30°F to 150°F, Storage (without media)
Relative Humidity 20 to 80% Operating, without Condensation
5to 98% Storage, without Condensation
Weight 13 lbs.
Outline Dimensions See Figure 1-2.
1-4 112670-103A

1.5 DISKETTE
The storage element used is atwo-sided ferromagnetic coated flexible disk
enclosed within aprotective plastic jacket. See Figure 1-3 for two sided
diskette and Figure 1-8 for one sided diskette. The interior of the jacket
is lined with awiping material to clean the disk of contamination. The
diskette is always kept in astorage and traveling envolope to further protect
the recording surface. Characteristics of the storage element are as follows:
Track Width: 0.014 inch
Track Spacing: 0.02083 inch (48 tracks/inch)
Disk Diameter: 7.875 inches
Envelope Size: 8x8 inches
1.6 RECORDING FORMAT
The format of the data recorded on the Diskette is totally afunction of the
host system and can be designed to the user's application to best take advan-
tage of the total available bit capacity of any one track or diskette.
The following are four examples of data formatting:
Figure 1-4 shows the IBM track format.
Figure 1-5 shows arecording format using index recording.
Figure 1-6 shows asample format used with MFM encoding.
Adiscussion of MFM encoding is contained in Section 2.5.2.
Figure 1-7 shows arecording format used with a32 sectored
diskette.
1.7 MAINTENANCE AND RELIABILITY
This section defines the long term unit reliability and data integrity of the
diskette drive.
1.7.1 DESIGN LIFE
The drive is designed and constructed, to provide auseful life of 15,000
power on hours or 5years. During the useful life repair or replacement of
parts is permitted. The read head is designed for aminimum of 30,000
hours operation.
1.7.2 RECOVERABLE READ ERROR
9
The recoverable read error rate is less than one error in 10 bits.
1.7.3 NON-RECOVERABLE READ ERROR RATE
12
The non-recoverable read error rate is less than one error in 10 bits read.
Aread error is defined in Section 3.3.8.2. Errors attributed to the diskette
are not included in determining the non-recoverable read error rate.
112670-103A 1-5

I
on
a-.s2«?5 up
lPiCi TYP F/IKSlQC.
4.63 2.02
ON
o
o
>
Ifl
7.47 ±Pb
-b-t>lxZt>VP
4PLCS
.2S*-Ol MW.00-*
lPLACED
Figure 1-2. Installation Drawing, Models RFD4000, RFD4001,
RFD2000 and RFD2001.

.U3 f-1
2PLACESj^
90°±0°30'
MMC 669
—-4.000 —-| |—.
.500 ±.005
K-250±.005
.550
2PLACES
-8.000±.0I5
Q] INDEX HOLE IN DISK.
[Tj INDEX HOLE IN JACKET -BOTH SIDES.
3. ALL DIMENSIONS ARE ±.010 INCH UNLESS OTHERWISE INDICATED.
4J CENTER OF MOUNTING HOLE TO CENTER OF INDEX HOLE IS 1.500 ±.002
INCH.
MOUNTING HOLE IN JACKET- BOTH SIDES.
MOUNTING HOLE IN DISK.
Figure 1-3. Two Sided Storage Element Physical Dimensions,
112670-103A 1-7

OO SINGLE DENSITY
26 SECTORS SINGLE DENSITY 15 SECTORS SINGLE DENSITY 8SECTORS DOUBLE DENSITY 26 SECTORS DOUBLE DENSITY 15 SECTORS DOUBLE DENSITY
8SECTORS
#KYTES HEX MBYTES HEX #BYTES HEX MBYTES HEX AWffiS HEX MBYTES HEX
as
PREAMBLE 40
6FF 00 40 6FF 00 40 6FF 00 80
12 4E
00 80
12 4E 00 80
12 4E
00
TRACK MARK 1FC
CLOCK =D7 1FC CLOCK =D7 1FC
CLOCK =D7 3
1C2 a; FC 3 1
C2 (1)
FC 3
1
C2 (1)
FC
GAP 126 FF 26 FF 26 FF 50 4E 50 4E 50 4E
o
IJ
w
M
Pi
o
H
u
H
V3
GAP 26 00 600 6 00 12 00 12 00 12 00
ADDRESS MARK 1FE
CLOCK =C7 1FE
CLOCK =C7 1FE
CLOCK =C7 3Al (2) FE 3 1
Al (2)
FE 3 1
Al (2)
FE
TRACK #101-4C 101-4C 101-4C j- 01-4C 101-4C 101-4C
SIDE #100-01 100-01 100-01 00-01 100-01 §100-01
SECTOR #101-1A 101-OF 101-08 01-1A 101-1A 101-08
SECTOR SIZE -128 x2N1N= 00 1N=01 1N=02 N=01 1N=02 1N=03
CRC-PREVIOUS 'Y' BYTES 2Y=5XX 2Y=5XX 2Y=5XX 2Y=8XX 2Y=8XX 2Y=8XX
GAP 311
6
FF
00 11 6
FF
00
11
6
FF
00 22 12 4E 00 22 12
4E
00 22 12
4E
00
DATA MARK 1FB(3)
CLOCK =C7
1FB(3)
CLOCK =C7
1FB(3) 3
1
Al(2)
FB(3) 3 1
Al(2)
FB(3) 3 1
Al(2)
FB(3)
DATA 1.28 B1
255 C4
5E 1 511 C4
5E 256 40 512 40 1024 40
CP.C PREVIOUS 'Z' BYTES 2Z=129 XX 2 Z =257 XX 2Z=513 XX 2Z=260 XX 2Z=516 XX 2Z=1028 XX
GAP 427 FF 42 FF 58 FF 54 4E 84 4E 116 4E
REPEAT SECTOR 'If TDES M=26 M- 15 M= 8M=-26 M=15 M= 8
TRAILING GAP 5247 FF 170 FF 311 FF 598 4F, 400 4E 654 4E
ON
-J
O
I
(1) Missing clock between bits 3and 4.
(2) Missing clock between bits 4 and 5.
(3) This is F8 for deleted data or IBM calls it "control data" when used on TOO Side Sector 8-26 and TOO
Side 1all Sectors. This is not applicable to the Data Warehouse.
(4) Initialize paramaters are estimated from other formats for which we have IBM Specs
.
(5) Track 00 Side is written similar to single density 26 sectors for all formats except data fields are different.
(6) Track 00 Side 1is written in 26 sector pattern either single or double density to match rest of diskette.
XX =CRC calculated by 1+x5+x12 +x16
PFigure 1-4. IBM Track Format. Hexidecimal Notation Used (X'00') In This Illustration.