Tandon TM 100 Instruction and safety manual

TAN DON MAGNETICS CORPORATION
9333 OSO AVENUE
CHATSWORTH, CALIFORNIA 91311
[phone]
'anaon
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023-6017
TM 100 DISK DRIVE
OPERATING &SERVICE MANUAL

SECTION I
TABLE OF CONTENTS
GENERAL DESCRIPTION AND SPECIFICATIONS. ........... .. 1
Introduction Purpose of Equipment ... Physical Description of Equipment ... Functional
Description Diskettes Mechanical and Electrical Specifications ... Interface Specifications .
Uncrating
tbe Disk Drive Physical Checkout ... Interface Connections ... Chassis Ground .
Mounting
the Disk Drive·. . . Diskette Handling and Storage . . . Loading the Diskette ...Write
Protect
... DC Power Requirements.
SECTION II THEORY OF OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . .. 9
Introduction
... Organization olthe Disk Drive ... Functional Block Diagram Description ... Index ...
Write Protect . . . Track 00 Switch ...Spindle Drive . . . Positioner Control ... Data Electronics
SECTION III OPERATION .........................•............... 14
PROPRIETARY NOTICE
Introduction ..• Physical Description of PCBA's ... Interface Electronics Specifications ... Circuit
Board Test Points
... Option Select ... Adjustment
Information contained in this document
is copyright by TANOON
MAGNETICS CORPORATION and may
not be duplicated in full
or in part
by any person without prior written approval of T AN DON
MAGNETICS CORPORATION. It is provided as an aid to the usef
with no guarantee, written
or implied, that the document is accurate
with regard
to any specification.
©copyright 1979 TANDONMAGNETICS CORPORATION
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figur.'4
Figure 15
liST OF ILLUSTRATIONS
TM 100 Disk Drive :...................................... .. 1
Recording Medium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 •• 3
Outline TM100 Disk Drive. . . . . . . 0 • 0 • • • 0 • • • • • • • • • • • • • • • • • • 0 • • •• 5
Diskette eare and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6
Diskette Access . . . • • . . . . . 0 • • • 0 0 • • • • • • • • • • • • • • • • • • • • • • • • • • 0 7
Write Protect Tab . . . . . . . . . . . . 0 • • • • • • • • • • • • • • •• ••••••••••• 08
TM100 FunctionatBlock Diagram 0 ••••••••••••••••••• 0 ••••• 10
FM .Aecording .0 • • • • • • • • • • • • • • • • • • • • • • • • 0 ••• • 0 • • • • • • • • • • • • • 11
Write Timing Diagram 0 • • • • • • • • • • • • • • 0 • • • • • • • • • • • • • • • • • • • • • • • 12
Read Timing Diagram 0 • • • • • • • • • • • • • • • • • • • • • • • 0 0 • • • • • 13
logic PoC.B.A 0 •••••••••••• 0 • 0 •••••••• 14
Servo P.C.B.A .•.. 0 •••••••••••••••••••••••••••••••••••••••• 15
Interface Configuration. . . .'. . . . . . . . 0 • • • • • • • • • • • • • • • • • • • • • • • • 0 • 15
Catseye Pattern. . . . . . . 0 • 0 • • 0 • • 0 • • • • 0 • • • • • • • • • • 0 • • 0 • • • • • • • • • 20
Index to Data .0 •••••••••• 0 •••••••••••••••••• 0 •• 0 •• 0 ••••• 0 21
LIST OF TABLES
Table -Mechanical and Electrical Specifications. . . 0 0 • • • 0 • • • • • • • • • • • 0 • • • 0 • 0 • o. 4
Table -Interface Connector Pin Assignments,
Jl/P1 0 •••••••••••••••••• 16
Table -Power Connector Pin Assignment 0 •••••• 0 ••••••• 0 0 ••••• 0 •• 16

SECTION I
GENERAL DESCRIPTION AND SPECIFICATIONS
1.1 INTRODUCTION
This section provides
the physical and functional specifications for the TM100 Disk Drive. manufactured by
TANDON MAGNETICS CORPORATION.
1.2 PURPOSE OF THE DRIVE
The TM100 Disk Drive is a "MINI" Disk Memory designed for random access data entry, storage, and
retrieval applications. These applications typically are intelligent terminal controllers, micro-computers. word
processing systems, data communications systems. error logging, micro-program loading. and point of sale
terminals.
The TM100 is capable of recording and reading digital data usingFM, MFM, or M2 FM techniques.
1.3 PHYSICAL DESCRIPTION OF THE DRIVE
The TM100 Disk Drive is shown in Figure 1. The Drives can be mounted in any vertical or horizontal plane;
however,
when mounted horizontally, the printed circuit logic board must be uppermost.
The spindle is belt driven by a de motor with an integral tachometer. The servo control circuit, suitably sized
pulleys,
and the tachometer control the speed of the spindle. The read/write double-sided head assembly is
positioned by means of a stepper motor, split band, and asuitablv sized puney.
The read/write/erase head assembly is aglass-bonded ferrite/ceramic structure which has afife in excess of
20,000 hours.
Operator access for diskette loading is provided via aslot located at the front of the unit.
The electronic components of the Drive are mounted on two PCDA's, one of which Hogic) is located above
the chassis, the other (servo) is mounted at the rear of the unit. Power and interfacesignals are routed through
connectors which plug directly into the logic PCBA.
TM 100 DISK DRIVE
Fig. 1

:;.~: :~~H' •I
6.30 I 0,25 mm
1015 I 0.0' 'NCIII
'33,4 10m
(5?5 INC'"
i
E~
e-
\1)(;
dO
+1·
~~
I!:?
L
(0
3fi6mm --J~~
ul'40 'NCIIl . ., 11 .. -lI
T
::.~; ,'::... ..1
(,f"-"'-'~
\
1.4 FUNCTIOhl"\L DESCRIPTION OF THE DRIVE
The Disk Drive. is futtyself-contained and requires'no operator intervention during normal operation. The
Drive consists of aspindle drive system, ahead positioning system, and read/write/erase system.
When the front latch
is opened, access is provided for the insertion of adiskette. The diskette is positioned in
place by plastic guides, and the front latch. Inlout location
is ensured·when the diskette is inserted until a
back stop is encountered.
Closing the front latch activates the conelclamp system resulting in centering of the diskette and clamping of
the diskette to the drive hub. The drive hub is driven at aconstant speed of 300 rpm by aservo controlled dc
motor. In operation, the magnetic head is loaded into contact with the recording medium whenever the front
latch
is closed.
The magnetic head is positioned over· the desired track by means of a4-phase stepper motor/ba,nd assembly
and its associatedelectronics. This positioner employs aone-step rotation to cause a1-treck Unear' movement.
When awrite-protected diskette
is inserted into the Ddve, the write;;protect senior disables the write
electronics of the Drive and an appropriate signal is applied to the interface.
When performing awrite operation, a0,33
mOl (0.013-inch) (nominal) data track is recorded. This ,track is
then tunnel erased to 0,30 mOl (0.012 inch) Cnominal).
Data recovery electronics include alow-level read amplifier, differentiator, zero-crossing detector, and
digitizing circuits.
No data decoding facilities are provided in the basic Drive.
The Drive
is also supplied with the. following sensor systems:
(1) ATrack 00 switch which senses when the Head/Carriage assembly is positioned at Track .,.
(2) The index sensor, which consists of an LED'Ught source andphototransistor, is positioned such
that when
an index hole is detected, adigital signal is guaranteed. The index sensor used is ahigh
resolution device which can distinguish holes placed close together, i.e., Index-Sector holes in a
hard sectored diskette.
(3) The write-protect sensor disable the Disk Drive electronics whenever awrite-protect tab is applied
to the disketteCsee section .1. 16 and figure 6).
1.5 DISKETTES
The TM 100 uses astandard 133.4mm (5.25 inch) diskette. These diskettes are available with asingle Index
hole
or multiple holes.
Diskettes with asingle hole are used when secto.rinformation is prerecorded on the diskette. Multiple hole
diskettes provide sector information by means of the index sensor andelectronicl.
Figure 2is asimpUfied drawing of the diskette used with the Disk Drive. It can be saenthat this recording
medium is aflexible magnetic disk enclosed in aprotective Jacket. The protected disk, free to rotate within
the jacket,
is continuously cleaned by th, soft fabric lining of the Jacket during normal operation. LINER
1.6 MECHANICAL·AND ELECTRICAL SPECIFICATIONS
The mechanical and electrical specifications for the Disk~rive are given in Table 1.
1.7 INTERFACE SPECifiCATIONS
Levels: True II: +O.4v(maximum)
False =+2.4v (minimum)
The interface circuits are designed so that adisconnected wire results in afalse signal.
1.8 UNCRATING THE DISK DRIVE
The Disk Drive is shipped ina protective container which, when bulk packaged, minimizes the possibility of
damage during shipment. The follOWing procedure describes thetecommended method for uncfatlng the Disk
Drive. (1) Place the container
on aflat work surface.
(2) Remove the outer cardboard sleeve from around the Inner container.
(3) Remove the upper half
of the inner-container.
(4) Remove the Disk Drive from the lower half of the inner container.
(5) Check the contents of the shippingcontainer against the packing sUp. Investigate the contents for
possible.damage; notify the carrier immediately If any damage Is noted.
RECORDING MEDIUM
Fig. 2
1.9 PHYSICAL CHECKOUT
Before applying power to the unit, the following inspection should be performed:
(1)
Front'atch. Check that the front latch opens and closes. Note that when the door is opened, the
head arm raises.
(2) Ensure that the front panel is secure.
(3) Manually rotate the drive hub. The
hub should rotate freely.
(4) Check
that PCBA's are secure. Check that the connectors are firmly seated.
(5) Check for debris
or foreign material between the heads and remove same.

TABLE 1
MECHANICAL AND ELECTRICAL SPECIFICATIONS
1.10 INTERFACE CONNECTIONS
Signal connections for the TM100 are made via auser·supplied 34-pin flat ribbon\., 'itor (3M Part No.
3463-0001
or equiva'end. This connector mates directly with thePCBA connector anile rear of the Drive.
The dc power connector
is afour-pin connector (Amp Mate-N-Lok, Part No. 1,.480424-0) which mates with
the connector on the logic PCBA at the top rear of the Drive. The interface description of the connectors,
and the location of each, Is contained in Section ",.
The signal connectorharnessshould be of theflat ribbon or twisted pair type with the following characteristics:
(1)M~ximum length of10 feet.
(2) 22 - 24 gauge conductor compatible with the connector to be used.
Power connections
shou'd be made wit,h18 AWGcable (minimum). In addition, the PCBA mounted dc power
connector
lskeyed.
Industrv-compatible 5%-inch diskette
48
Media
Tracks per inch
Number of Tracks
Dimensions
Height
Width
Depth
Weight
Temperature
(Exclusive
of Media)
Operating
Non-operating
80 (40 per side)
85,85 mm (3.38 inches)
149,10 mm (5.87 inchest
203,2
mm (8.0) inches
2.04
Kg (4.5 IbsJ
10
0e
to 44°C (GOoF to 112°F)
-40°C to 7,oe (-400F to 16ooF)
1.11 CHASSIS GROUND
To ensure proPer operation of the Drive, the chassis should be connected to earth ground. The 3116" male
ac lug, 'Clcated at the rear of the chassis, 'sprovided ·to facilitate this connection.
1.12 MOUNTING THE DISK DRIVE
The Drive has been designed such that it can be mounted in any plane, i.e., upright, horizontal, or vertical.
The only mounting restriction
is that when mounted horizontally, the logic peBA side of chassis must be the
uppermost side. Tapped holes
.feprovidedin various loc:;ations for the attachment of user supplied hardware.
Figure 3shows
the location of the recommended mounting holes.
+-t-t·
fiJ
3.12
I
,~
Hn
I
L-3~-1
lOGIC PC8.A
REF.
•5,81 •
iI
5,75 •
13 __ '" 5.50
.06 .-..., ~-.....- .m
~ 1
m
I ~
,..;
I
lLD
CIO
~jJL---II' It gill "'IF' UUII " • I
.--,
.~ ~
FM,MFM,MMfM
FM 125K bits/sec
MFM 250K bits/sec
20,000 hOUfS (normal use'
15 msec (last track addressed)
per
10
9(recoverable)
per
10
'2
(non-recoverable)
per
10
6(seeks)
2.00 million (FM)
5msec track to track
250/150 msec (maximum)
3.6 x 10
6passes Per track
300 rpm:!: 1.5% (long term)
~ 3.0%
20% to 80% (Non-condensing)
5% to 95% (Non-condensing)
Relative Humidity
(Exclusive
of Media)
Operating
Non-operating
Disk Speed
Recording Modes (typicaU
Head
life
Error Rate
Media
life
Head Setting Time
Bits/Disk (unformatted)
Instantaneous Speed Variation
Transfer
Rate
Seek Time
Start/Stop Time
Power +12
de ~ O.6v 900 ma AVE.
+5v dc ±0.25v,
600 ma AV E.
OJ
FOUR. ,•.t MOUNTING HOLES
,. ON UNIT FARStOEC80lTOMt.
No, 6·32 UNe 18 ".31 OP
r;l FOUR '4t. MOUNTING. HOLES.
~ TWO f2t ON EACH SlOE
No, 6·32 tJNe 28 ".31 OP
OUTLINE -TM100 DISK DRIVE
Fig. 3
45

1.12.1 HARDWA.
The Disk Drive is manufactured with certain critical internal alignments that must be maintained. Therefore,
it
is important that the mounting hardware does not introduce significant stress on the Drive.
Any mounting scheme
in which the Drive is part of the structural .intergrity of the enclosure is not permitted.
Mounting schemes should allow for adjustable brackets or incorporate resilient members
to accommodate
tolerances.
Mounting schemes involving more than three mounting points should
be avoided.
1.12.2OUST COVER
Since the Disk Drive is not provided with adust cover, the design of an enclosure should incorporate ameans
to prevent contamination from loose items, e.g., dust, lint, paper chad, etc.
1.12.3COOLING
Heat dissipation from asingle Disk Drive is normally 15 watts (51 Btu/Hr) under hi",Uneconditions. When
the Drivels mounted so that the components have access to the free flow ofafr,normal convection cooting
allowsoperation over the specified temperature range.
When the Drive is mounted in aconfined environment, air flow must be provided to malntain specified air
temperatures in
the vicinity of the motors, PCBA's, and diskette.
1.12.40RIVE SEPARATION
In addition to the cooling requirements specified in Paragraph 1.12.3, aminimum separation of 26,4mm
(1 inch) between·Drives is recommended. This is required to avoid electrical interference between themotors
of one Drive and the magnetic head of another Drive. Closer mounting
is allowable If agounded sheet of steel
at least 1,52 mm (O.060-inch) thick is placed between units. However, use of this steel sheet may increase the
cooling requirements.
1.13 DISKETTE HANDLING AND STORAGE
It ·is important that the diskette be handled and stored properly so that the integrity of the recorded data is
maintained. Adamaged
or contaminated diskette can impair or prevent recovery of data and can result in
damage
to the read/write heads.
/
Figure 2illustrates the physical configuration of the diskette. The diskette is an oxide coated, flexible mylar
disk, 130,2 mm (6.125 inches) in diameter, and is enclosed in an 133,4 mm x 133,4 mm(5.25x 5.25-inch)
protective jacket. Read/write/erase head access
is made through an aperture in the jacket. Openings for the
drive hub and diskette index hole are also provided.
Figure 4provides some helpful
hi~lts on the care and handling of the Disk Drive and diskettes. Additionally,
to assure trouble-free operation and enhance the service life of the diskette, the following procedures for
handling should
be observed:
Return the diskette to the protective jacket when not in use.
Avoid exposing the diskette to any mangetizing force in excess of 50 oersted.
NOTE
The 50 oersted level of magnetizing force is reached at adistance
of approxilnately 76 mm (3 inches) from atypical source, e.g.,
motors, generators, transformers.
Do not stare the diskette in direct sunlight as warping could resutt.
Do not use alead pencit or ballpoint pen to write on the label. Use afelt tip pen and mark IightiV
on the label.
1.14 LOADING THE DISKETTE
Diskette. loading is accomplished by inserting the properly oriented diskette.into the front slot provided.
Access tathe diskette loading slot is obtained by opening the front latch. See Figure 5.
The diskette should· be carefully inserted untit the diskette jacket is solidly against the backstop.
CAUTION
DAMAGE TO THE CENTER HOLE
IN THE DISKETTE MA Y
RESULT
IF THE DOOR IS CLOSED WHEN THE IJISKETTE IS
NOT PROPERLYINSERTED. THIS WILL PREVENT RELIABLE
RECOVERY OF THE RECORDED DATA.
"'"
"""''-
",-
'\.'.".
TO AVOID DAMAGE TO THE DISKETTE
AND TO YOUR DRIVE, INSERT OI$KUTE
CAREFUllY UNTtl BACKSTOP IS
ENCOUNTERED
RETURN lUE OISKETtE fO ITS JACKel
WHEN NOT I.N USE
.
KEE' DISKETTE AWAV FROM
MAGNEnC FIEt-OS.
00 NOT TOUCH PRECISION SURFACE
WITH YOUR FINGERS
UANOLE Wlnt CARE BENDING
AND FOLDING MAY DAMAGE
DISkETTE
OISKETllS SltOULO BE STORED At
,00 10 5l'1C
to" 10 I2S
Qf
DISKETTE CARE AND HANDLING
Fig. 4
DISKETTE ACCESS
Fig. 5

1.15 WRITE t,~",eCT
The Disk Drive is equipped with awrite protect switch assembly. This sensor operates in conjunction with a
diskette having aslot
cut in the protective jacket. The location of the slot is shown in Figure 6.
When the slot
is covered with aself-adhesive tab, the diskette is write protected. The slot must be uncovered
to write on the diskettE!. Figure 6illustrates how to instan a tab to cover the slot.
2.1 INTRODUCTION
SECTION II
THEORY OF OPERATION
WRln PROffcr TAO
~
@o
O·
fOlO OVER OACI< Of Ol<;t<fl f[
@.
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-~ .... ", .. ",,,n
TAO
This section provides a ba.sic description of the operation of the TANOON MAGNETICS CORPORATION
TM100 Disk Drive.
The Disk Drive consists of
the mechanical and electrical components necessary to record and read digital data
ana diskette. DC power at +12 vand +5v (provided by the user) is required for operation.
2.2 ORGANIZATION OF THE DISK DRIVE
All electrical subassemblies in the Disk Drive are constructed with leads which terminate in 4or 5pin
connectors. enabling the individual. assemblies
to be removed.
The magnetic heads are connected
to the PCBA via cables terminated in 5-pin female connectors and its
associated male sockets which are localed in close proxi.mityto the read/write data electronics.
Interface signals
and power are provided via connectors at the rear of the Drive. Detailed description of these
signals are presented in Section
til of this manual.
2.3 FUNCTIONAL BLOCK DIAGRAM DESCRIPTION
Figure 7 is functional block diagram of the TM 100 Disk Drive and $hould be referred to in conjunction with
the following discu$sion: NOTE
The identification of the elements of this discussion and the
associated figures are related
to the actual schematic and are
only represented in simplified form in this section.
6.30
r IO'~ INCH,
I-- 356 mrn
-I!--'- ";t4 'NCH'
,- -------11
Tf
96.5 mm
"~lNC"'
INDEX ACCESS HOLE
WRITE PROTECT TAB
Fig. 6
1.16 DC POWER REQUIREMENTS
+12:!:O.6vdc: 900MA (MAX AVE.)
+6 :!:O.25v de: 600 MA (MAX AVE'), <lOOmv P.P. ripple
8
The Disk Drive con$ists of
the following functional groups:
*Index Pulse Shaper
*Write Protect Sensor
*Track 00 Sensor
•Spindle Drive Control
*Carriage Position Control
•Write/Erase Control
•Read Amplifier
and Digitizer
2.5 INDEX
An index pulse is provided to the user system via the INDEX PULSE interface line. The index circuitry
consists of an Index LED, Index
Photo Transistor, and aPulse Shaping Network. As the index hole in the
disk passes the Index LED/Photo Transistor combination, light from the LED strikes the Index Photo
Transistor causing it
to conduct. The signal from the Index Photo Transistor is passed to the Pulse Shaping
Network which produces apulse for each hole detected. This pulse
is presented to the user on the INDEX
PULSE Interface tine.
2.6 WRITE PROTECT
AWrite Protect signal is provided to the user system via the WRITE PROTECT interface tine. The write
protect circuitry consists of aWrite Protect Sensor and circuitry' to route the signal produced.
When awrite
protected disf<ette is inserted in the drive, the sensor is activated and the logic disables the
write
~Iectronics and supplies the status signal to the interface.
2.1 TRACK" SWITCH
The level
on the TRACK 00 interface line is afunction of the position of the magnetic head assembly. When
the head. is positioned at Track 0. and the stepper motor is at the home position, atrue level is generated
and sent to the user.
2.8 SPINDLE DRIVE
The Spindle Drive system consists of aspindle assembly driven by a dcmotor-tachometer combination
through adrive belt.
Associated with the spindle drive
motor are the servo electronics required for control.
The control circuitry also includes acurrent limiter
and an interface control line. When the DRIVE MOTOR
ENABLE interface line
is true, the drive motor is allowed to come up to speed. When the current through the
drive
motor exceeds 1.3 ampere, the current limit circuitry disables the motor drive.
9

TM 100 FUNCTIONAL BLOCK DIAGRAM
I
I
1- / :
I I
I •
I •
-H BIT CEll~_
I 1 I 1
I • I
I I I
II I
I!I
NWRITEOATA
BITPATT£RN
MAGNETIZATION • 1
Fig. 8
MAGNETIC El~MENTS >( Y' )"' >f Y. 7)( If ¥ .... G·;:.f II 'i
F M RECORDING
2.10.1 DATA RECORDING
Referring to Figure 7, it c~n be seen that the Write Electronics consist of aWrite/Erase Current Source and
Write Waveform Generator, Erase Current Source, Trim Erase Control Logic,
a'1d Head Select Logic.
The read/write winding
on the magnetic head is center-tapped. During awrite operation, current from the
Write Current Source flow in alternate halves of the winding under control of the Write Waveform Generator.
Before recordinr can begin, certain conditions must be satisfied. The conditions required for recording
O.e., unit ready must be established bV the us,er system as follows:
CH Drlvespeed stabilization. This condition will exist 250 msec after starting the drive motor.
(2) Subsequent to any step operation, the positioner must be allowed to settle. This requires 20msec
total after the last step pulse is initiated, i.e., 5msec for the step motion and 15 msec for settling.
,i
DC STEPPER MOTOR
WHITE
"Honel
<4 .. _-_._-- .-----'
INlHtfACE
CONTUOl
IND[)(
PlltSf-
Fig. 7
2.9 POSITIONER CONTROL
The Head Positioning system utilizes afour-phase stepper motor drive w"ichchanges one phase for each
track advancement
of the Read/Write carriage. In addition to the logic necessary for motion contro', agate is
provided as an element for inhibiting positioner motion during awrite operation.
2.10 DATA ELECTRONICS
Information can be recorded on the diskette using adouble-frequency code. Figure 8illustrates the
magnetization prQfiles in each bit cell for the number sequence shown.
The erase gaps provide
an erased guard band on either side of the recorded track .. ·T .... is accommodat«!s the
tolerances in track positioning.
All signals required to control the data electronics are provided bV the user systemand are shown in the block
diagram, Figure 7. These control signals are:
•SELECT
•WRITE.ENABLE
•WRITE
DATA
* SI DE SELECT
The READ DATA composite signal is sent to the user system via the interface.
I"
.I
NOTE
All of the foregoing operations can be overlapped, if required.
Figure 9shows the relevant timing diagram for awrite operation. At t :::: 0when the unit is readv, the WR ITE
ENABLE interface line goes true, this enables the Write Current Source.
Since
the trim erase gaps are behind the read/write gap, the TRIM ERASE control goes true 390 usee after
the WAITE ENABLE interface line. It should be noted that this value is optimited between the requirements
at Track 0. and Track 34 so that the effect of the trim erase gaps on previous informati.on is minimized.
Figure 9shows the information
on the WRITE DATA interface line, and the output of the Write Waveform
Generator which toggles on the leading edge of every WAITE DATA pulse.
Note that aminimum of 4usee end amaximum of8 usecbetween WRITE ENABLE going true and the first
WRITE
DATA pulse is only required if faithful reproduction olthe first WRITE DATA transition is significant
At
the end of recording, at least one additional pulse on the WRITE DATA line must be inserted after the
last significant WRITE
DATA pu'se to avoid excessive peak shift effects.
The TRIM ERASE signa' must remain true for
800 usec after the termination of WRITE ENABLE to ensure
that aU recorded data are trim erased.·This value is again optimized between the requirements at Tracks 0.
and 34.
The duration
of awrite operation is from the true-going edge of WRITE ENABLE to the false-going edge of
TRIM ERASE. This
Is indicated by the internal WRITE BUSY waveform shown.

, ~ 0
WAITE ENABLE
'RIM ERASE
INTERNAL
WAllE BUSY
NWAITEOATA
WAITE
WAVEFORM
GENERATOR
WRITE CURRENT
NOTE 1,
II 1i--f~1 ,--L
I It· r-"J
390 ~ sees~' I ~ 800 -..J
I I 1 1 I users I
I 'J-; III s--r
I I I S. ~
II 1 S~
It ~
I r-:--t
tI
I
fNOTE 1
LINEAR OUTPUT FROM
FitTER
OUTPUT FROM DIFFERENTIATOR
READ DATA INTERFACE
t
t=0
NOTES: t= 0 =250 MILLISECONDS AFTER DRIVE MOTOR STARTS,
OR
20 MILLISECONDS AFTER STEP COMMAND, OR
100 uSECONDS AFTER TERMINATION OF WRITE
BUSY, (WHICHEVER
IS THE LATEST TIME)
NOTES
I ~ 0 ~250 M'LLISECONOS AFTER OAIVE MOlOA
STAATS OR 2OMIlliSECONOS AFTER LAST STEP
PULSE, 4WH'CHEVER 'S THE LATEST TIME)
WRITE TIMING DIAGRAM
Fig. 9
UNSYNCHRON'ZEO
8.5 MI\ PEAK TO PEAK
.. u SECONOS M'NIMUM, 8 " S£CONOS MAXIMUM
READ TIMING DIAGRAM
Fig. 10
2.10.2 DATA REPRODUCTION
The Read Electronics consist of the following:
*Read Switch/Side Select
*Read Amplifier
*Filter
*Differentiator
*Comparator and Digitizer
The Read Switch
is used to isolate the Read Amplifier from the voltage excursion across the magnetic head
during awrite operation. The side select
is used to enable one of the read/write/erase heads.
Before reading
can begin, the Drive must be in aready condition. As with the data recording operation, this
ready condition must
be established by the user system. In addition to the requirernents established in
Paragraph 2.10.1 a
100 usee delay must exist from the trailing edge of the TAIMERASEsignat to allow the
Read Amplifier to settle after the transient caused by the Read Switch returning to the Read mode.
Referring
to Figure 10, the output signal from. the read/write head is amplified bya read amplifier and
filtered to remove noise by alinear phase Filter. The linear outpUt from the Filter is passed to the
Differentiator which generates 8waveform whose zero crossovers correspond to the peaks of the read
signal. This signat
is then fed to the Comparator and Digitizer circuit.
The Comparator
and Digitizer circuitry generates a 1 usee READ DATA pulse corresponding to each peak of
the read signal. This Composite Read Data signal is then sent to the user system via the READ DATA
interface line.
l'

SECTION III
OPERATION
3.1 INTRODUCTION
This section
contains the interface description and the mechanical/electrical adjustments necessary for the
TM100 Disk Drive. Also presented are schematic diagrams of the PCB A's installed in the Disk Drive.
3.2 PHYSICAL DESCRIPTION OF THE PCBA's
The logic PCBA is approximately 146 mm (5.75 inches) tong by 146 mm (6.75 inches) wide, and' the
servo PCBA is approximately 127 mm (6.0 inches) long by 38 mm (1.5 inches) wide. Figures 11 and 12
illustrate the placement of test points and connectors.
R4 SPINDLE
SPEED CONTROL
ooSERVO JUMPER
DRIVE MOTOR
SERVO P.C.B.A.
Fig. 12
LOGIC P.C.B.A.
Fig. 11
• TRUE
14lS04 OR EOU.VAlENT
150 OHMS
~, 10 FEET
TWISTED PAIR
TRANSMISStON .LINE
DRIVER
Fig. 13
t
I
I
I
I
I
t
I
I REeEtVER
I
I
I
I
INTERFACE CONFIGURATION
I
I
I +'
I . I
L '~6 ~~E~:V~~~
r --------1
I '"" '" ~ I
+ TRUE
.5V
3.3 INTERFACE ELECTRONICS SPECIFICATIONS
All Interface signals are TTL compatible. Logic true· (low) is +0.4v (maximum), logic false (high) is +2.4v
(minimum). Figure 13 illustrates the interface configuration. Maximum interface cable length is 10 feet.
It Is recommended that the interface cable be flat ribbon cable, with acharacteristic impedance of 100
«>hans Cor equivalent twisted pairs).
Interface connector pin assignments and power connector pin assignments are given in Table 2 and Table 3.
3.3.1 INPUT CONTROL LINES (See Table 2.
3.3.1.1 SELECT LINES (NDS1-NDS4)
The SELECT lines provide ameans of selecting and deselecting aDisk Drive. These four lines (NDSO-NDS3
standard) select
one of the four Disk Drives attached to the controller. When the signal logic level is true
(low). the Disk Drive electronics are activated and the Drive is conditioned to respond to step or read/write
commands. When
the logic level is falseChigh). the input control lines and output status tines are disabled.
ASELECT line must remain stable in the true Clow) state until the execution of astep or read/write
command is completed.
The Disk Drive address is determined by aSelect Shunt on the PCBA. SELECT lines 0-3 provide ameans of
daisy-chaining amaximum of four Disk Drives to acontroller. Only one line can be true (low) at atime.
An undefined operation might result if two.
or more units are assigned the same address or if two or more
SELECT lines
are in the true Clow) state simultaneously.
o
TP3 •
TP10 •
TP4 •
•TP8
TPI •
TP2 •
t
~~
ii
TPI, •
STEPPER
1P9 AI MOTOR
I II· TN T~13 / %SERYO ~ER'
~'..
•• P6 ,.p,o. p"mpl3 ~ .•. I ..•. -- . J2.
~y
.. .-.- -', ".
J4 POWfR
~~~Y-CONNECTOR
TERMINATOR In0 0 0I
SOCKET'2F1 %.. ','- :1 ,
~ ~o ~ :
a :~ ! ~
c(
~
0:
WQ
~~
..1%
1Pl.
.TP5
~~
:>%
C48~~~)(i~
%Zzzz25!. TPH
o
PROGRAMMABLE
SHUNT
SOCKET HE.
/
.UNUSEO
Jl ,NTERfACE I}O INTERfACE
CONNECTiON CONNECTIONS
J3 READ/WRITE
HEAD CONNECTORS'RM
P5 P6

TABLE 2
INTERFACE CONNECTOR PIN ASSIGNMENTS.
J1/P1
3.3.1.2 DRIVE MOTOR ENABLE (NMOTORON) ,
When this signal line logic leve' goes true (low), the drive motor accelerates to its nomin~T;~eed of 300 rpm
and stabilizes in 'ess than 250 msec. When the logic level goes false (high), the Disk Drive decelerates to a
stop
Ground
Signa'
12
34
5 6
9
10
11
12
13 14
15
16
17 18
19
20
21 22
23
24
31
32
-
-
Ground
Signal
78
25
26
27 28
29 30
33
34
Controller-to-Disk Drive
Description (Mnemonic)
Connector clamp
(Spare)
SELECT 3(NOS3)
SELECT 0(NDSO)
SELECT 1(NDS1)
SELECT 2(NDS2)
DRIVE-MOTOR ENABLE (NMOTORON)
DIRECTION
STEP (NSTEP)
WRITE DATA (NWRITEDATA)
WRITE GATE (NWRITEGATE)
SIDE SELECT (NSIOE SELECT)
Disk Drive-to- Controller
Description (Mnemonic)
INDEX (NINDEX/SECTOR)
TRACK
00 (NTRK00J
WRITE PROTECT (NWRITEPROTECT)
READ DATA (NREADDATAJ
Connector Clamp
3.3.1.3 DIRECTION and STEP Lines (2 Lines) CDIR) eNSTEP)
Whe'n the Disk Drive is selected, a true (low) pulse with a time duration greater than 200 nsec on the STEP
Hne initiates the access motion. The direction of motion is determined by the logic state of the DIRECTION
line when aSTEP pulse is issued. The motion is towards the center of the disk if the DIRECTION line is in the
true (low) state when aSTEP pulse is issued. The direction of motion is away from the center of the disk if
the DIRECTION line is in thefa1se (highl state when aSTEP pulse is issued. To ensure proper positioning
the DIRECTION line should be stable 0.1 usec (minimum. before the trailing edge of the corresponding
STEP pulse
and remain stable until 0.1 usee after the trailing edge of the STEPpufse. The access motion is
initiated on the trailing edge of the STEP pulse.
3.3.1.4 WRITE DATA (NWRITEDATA)
When
the Disk Drive is selected, this interface line provides the bit-serial WRITE DATA pulses that control
the switching of the write current in the heads. The write electronics must be conditioned for writing by the
WRITE ENABLE line (see Paragraph 3.3.1.5).
For each high-to-Iow transistion on the WRITE DATA line, aflux change is produced at the head write gap.
This causes a
·nux change to be stored on the disk.
When the double-frequency type encoding technique is used Cin which data and clock form the combined
Write Data signa1). it is recommended that the repetition of the high-to-Iow transitions, when writing aU
zeros, be equal to the nominal data rate ±0.1 percent. The repetition rate of the high-to-Iow transitions,
when writing aU ones, should be equal to twice the nominal data rate, ±O.1 percent.
3.3.1.5 WRITE ENABt.E CNWRITEGATE)
When this signal is
true (lowtthe write electronics are prepared for writing data (read electronics disabled).
This signat turns on write current in the read/write head. Data is written under control of the WRITE DATA
input line. It is generally recommended that changes of state on the WRITE ENABLE line occur before the
first WRtTEDATA pulse. However, the separation between the teadingedge of WRITE ENABLE and the
first significant WRITE DATA pulse should not be less than 4usee and not greater than 8usec. The same
restrictions
exist for the relationship between the least significant WRITE DATA pulse and the termination of
the WRITE ENABLE signal. When the WRITE ENABLE line is false (high). all write electronics are disabled.
When a
write·protected diskette is installed in a TM100 Disk Drive, the write electronics are disabled
Irrespective
of the state of the WRITE ENABLE LINE.
3.3.1.6 SIDE SELECT (NSIDESELECT»
When this signal is
true (low) side 1 of the disk is selected forread/write operations. When the signal is
false (high) side 0 of the disk is selected. This signal must be stable during an entire read or write operation.
This
signatis best implemented in sychronization with the device select line signal. (See Paragraph 3.3.1.1J
TABLE 3
POWER CONN,ECTOR PIN ASSIGNMENT
Pin Supply Voltage
1+12v
de
2
Return (+ 12v de)
3
Return C+5v det
4+5v de
16
3.3.2 OUTPUT STATUS (See Table 2»
3.3.2.1 INDEX (NtNDEX/SECTORI
The INDEX signal is provided once each revolution (200 msec, nominal) to indicate to the controller the
beginning of atrac·k. The INDEX line remains in the true (low) state for the duration of the INDEX pulse.
The duration of an INDEX pulse is nominally 4.0 msec.
The leading edge of an INDEX pulse must always be used to ensure diskette interchangeability between Disk
Drives.
3.3.2.2 TRACK .e (NTRK")
When the Disk Drive is selected, the TRACK 00 interface signal indicates to the controller that the read/
write
head is positioned at Track 00. The TRACK 00 signal remains true (low) until the head is movedaway
from Track 00.
3.3.2.3 WRITE PROTECT (NWRITEPROTECT)
When
the Oisk Drive is selected, this signal line 'ogic level goes true (low) when the diskette is write protected.
The write electronics are internally disabled when the diskette is write protected.
NOTE
It ;s recommended that the write data line be inactive whenever
Write Enable
is fillse (i.e., read stateJ.
When the level on this line is false (high), the write electronics are enabled and the write operation can be
performed. It is recommended that the con trotter not issue a write command when the WRITE PROTECT
signal is
true (low)_
17

3:~~3.2.4 REAL ,/A (NREADDATA'
This interface line transmits the readback data
to the controller when the Drive is selected. It provides apulse
for each flux transition recorded
on the medium. The READ DATA output line goes true Uow) for aduration
of 1usec for eachf'ux change recorded.
The leading edge of the READ DATA output pulse represents the true positions for the flux transistions on
the diskette surface.
3.4 CIRCUIT BOARD TEST POINTS
The following test point description assumes
that the logic and servo peDA's are installed in aTM100 Disk
Drive and that the Drive is in an operational mode with 8diskette installed.
3.4.1 LOGIC GROUND (TP6)
Digital
logic ground is referenced at TP6.
3.4.2 DIFFERENTIATED READ SIGNAL (TP3, TP4)
.These test points are provided to .observe the differential output of the second stage· amplifier and
differentiated read signal.
3.4.3 READ DATA SINGLE SHOT (TP5)
The
output of the single shot used in the read section is nominally 1.0 usec for each flux transistion detected.
3.4.4 INDEX PULSE (TP7)
With astandard soft sectQred diskette installed, the signal ishigh going pulse nominally 3.5 msec in.duration
every 200 msec.
3.4.5. AMPLIFIED READ SIGNAL (TP1. TP2)
These test points are provided to observe the differential output of the first stage of read signal amplification.
3.4.6 MOTOR ON (TP13)
This signal
is low true for the "motor on" condition.
3.4.7 TRACK
It (TPI'
This signal is low true when the carriage is positioned at track 01 and the step motor phase is correct.
3.4.8 ANALOG GROUND
CTP10)
Analog ground reference point is provided for measuring read/write waveforms.
3.4.9 (TP11) NOT FOR USE
3.4.10 STEP PULSE (TP12,
When stepping
inor.out the·signal is ahigh going pulse for each step of the carriage.
3.4.11 WRITE PROTECT SWITCH (TP9)
When awrite protected diskette
is installed in the Drive the signal is high.
3.5 OPTION SELECT
3.5.1 INPUT LINE TERMINATIONS
The TM100 has been provided with tne capability
of terminating the input lines listed below:
•Motor On
•Direction Select
*Step
*Write Data
•Side Select
These lines are terminated through a160 ohm resistor pack installed in adip socket located at IC location 2F.
In asingte drive system this resistor pack should be kept in place to provide the proper terminations.
In amultiple drive system (Program Shunt position
"MX" open. only the last drive on the interface is to be
terminated. All other drives on the i·nterface must have the resistor pack removed.
3.5.2 DRIVE SELECT 1-4
The TM100 as shipped from the factory;s configured to operate in asingle drive system. It can be easily
modified by the user to operate with other drives in amultiplexed multiple drive system. The user can
activate the multiplex option
by cutting.the ·'MX"position of the programmable shunt located in Ie location
IF. This will allow the multiplexing of the I/O lines.
18
In amultipl.e drive system (program shunt position "MX" open) the three input lin~$/(Orive Select 1,
Drive. Select 2and Drive Select 3) are provided so that the using system may select which drive on the
interface
is to be used. In addition, Drive Select 4 is provided as an option. In this mode of operation, only
the Drive with its Drive Select Une active will respond to the input Unesand gate the output tines.
The program shunt, IC location 1 E, positions "OS1", "052" and "OS3", are to be used to select which
Drive Seleet tine will activate the I/O lines for aunique drive. As
an example, if the user wants the first drive
on the interface to be addressed as drive #1, he must cut program shunt positions "OS2" and "OS3", and
leave" OS 1" intact.
The program shunt
is AMP part number 436704-7. The shunt positions can be cut using AMP's tool part
number 435105. The shunt
is installed in adip socket and at the user's option be removed and replaced by a
dip switch. The user may also choose
to have the program shunts pre-programed and/or color coded by AMP.
Forth's service contact your local AMP representative.
3.6 ADJUSTMENT
3.6.1 CE ALIGNMENT
The CE alignment procedure locates the magnetic read/writ. head at the proper radial distance from the hub
centerline, thus assuring accurate track location. This adjustment is necessary·onty after service, or for
suspected diskette·interchange problems.
3.6.1.1 DISK DRIVE·PREPATATION
(H Apply the necessary power and control to turn on the Disk Drive.
(2) Insert aCE Alignment Diskette (Oysan Part No. 224-2A or equivalent) into the drive and close
the front latch.
(3) Attach oscilloscope lignat probes to· test points TP1 and TP2. Place ground clip of signal probes to
tPl0. Adjust the oscilloscope to read differentially (A +Bwith Binverted). Sync the oscilloscope
on the leading. edge of the Index. pulse at TP7 with sync probe ground clip at TP6.
3.6.1.2 RADIAL TRACK ALIGNMENT
(1' Select HO " ....
(2. Loosen· (do not remove' the two module retaining screws on the bottom of the chassis, and the one
atthe top rear of modute.
C3' Follow instructions accompanying the CE Diskette.
(4' Manually rotate the cam at the rear of the modula until the cats-eye pattern shown in Figure 14 is
observed. Carefully rotate the cam untit the cats-eye pattern has equal.· amplitudes.
(5t Secure the module by tightening the t3' retaining screws, previously loosened.
(6' After securing the module screw, verify Step (4). Repeat as required.
(7) Check H01 ensures lobes are within 80% of each other.
3.8.1.3 INDEX SENSOR ALIGNMENT
(1) Position the Index sensor to center of trave'; lightly tighten retaining screw.
(2lPerform
CE alignment as required to locate the cats-eye pattern (refer to Paragraph 3.7.1.2'.
(3) Perform fifteen step out commands to position the carriage to Track '1.
(4' Set oscilloscope horizontal time base to 50 usee per division.
(5) Referring to figure 15. adjust photo transistor mounting block until the first transistion of the
2
msec burst (ecorded at Track '1 occurs 200 !50 usee after the leading edge of the .Index
pulse. Adjustment may be made with the use of aflat-bladed screwdriver placed between the
photo transitor mounting block and chassis as required.
(6) Secure retaining screw on the photo transistor mounting block and verify burst location;
readjust as necessary.

TIME SCALE 20 mslOtV
TIME SCALE
... 20 mslOIV.
CATSEVE PATTERN
Fig. 14
20
EOUAl AMPltTUO£
CON TRACK '6.
ONE IS 8~ OF THE OTHER
UMtL OFF TRACKJ
l' 't,'
INOEXJ'tO O'ATA
Fig. 15
3.6.2 TRACK" SWITCH
(1 t ApplV the necessary power and contro' to turn on the- Drive.
(2) Insert the CE Alignment Diskette into the drive and close the hont latch.
C3J Position the carriage to the radiai alignment track. Confirm the position by observing the cats-eye
patter'n.
(4)11 adjustment is required, remove theCEOiskette. loosen the retaining screw on the base of the
Track"Bracket. retighten slightly to provide some friction on the bracket and rotate the Track
•• Adjustment Screw (located atth' rear of the chassis) counter-clockwise as far as It will go
without forcing it.
(&) Position the carriage to Track" by performing repetitive step out pulses.
(6) Rotate the Track ... Adjustment Screw clockwise-very .'ow1y-until the switch "clicks". Then
rotate the screw clockwise' (same directiont exact.ly one hall turn.
(7) Tighten the retaining screwperviously loosened.
3.6.3 WRITE PROTECT SWITCHES
(1) 'flsert anOfl-write protected diskette·partially (halfway) into the Drive.
(2) Ensure that the switch is actuf,lted.
(3) Insert diskette fully·against diskette back stop and close the front latch. Ensure that the switch is
deactivated.
(4) Adjust switch by loosening the retaining screw, removing switch assembly and setting switch higher
or 'ower as required.
3.6.4 DRIVE MOTOR SPEED
(1) Apply nt?~essary power andcootrol to turn on the drive.
(2) Insert drskette:
(3) Ensure that Qri~e ,Motor Enabht-line is active.
14) Adjust Speed ·Control.potentiomete~ .(on servo peDA) until timing disk is stationary in fluorescent
lighting.
21