Sharp MZ-80SFD User manual

SHARP
SERVICE MANUAL
PDSMX81014-MZ
Single Floppy Disk
MZ-80SFD
FEATURES
•High speed reading and writing of data and programs.
•
Easy deletion and addition of programs.
•Simultaneous reading and execution
of program by "RUN" command.
•
Linking programs by "CHAIN, SWAP" command.
•Expanding up
to four drives by one I/O card.
SHARP CORPORATION

------------Contents--------~'\
Specifications 1
Constitution
of single floppy 1
Operational principle
of floppy disk " 2
Inspection and replacement
of disk drive main parts ......................... .. 6
Trouble shooting guide
11
Power supply section. ............................................. .. 13
Circuit diagram and printed wiring board 15
Packing method .................................................
.. 20
Disassembled views ' . . . . . . . . . . . . . . . . . .. 21
Replacement parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 23

Item Specification
>------ -----
--_.
Drive-to-drive connection Daisy-chain system
(a maximum of four drives)
-----------------------
Recording medium 5.25-inch both-sides flexible disk
--
Recording Double
or single density
---
Number of tracks 70 tracks
Sector
Soft sectored
---
Formatted capacity
280K bytes/drive at 16 sectors/track (double density)
140K bytes/drive at 16 sectors/track (single density)
Power supply AC
220V ±10%, 50Hz
AC 240V ±10%, 50Hz
---_._-
-
Power Consumption 30W
---- ~._-----~---_._--
Operating conditions 5
to 25°C in temperature
20
to 80% in humidity (free of moisture condensation)
1----
------
-
External dimensions
Approx. 165 (W) x102 (H) x323 (D) mm
Weight 4
kg
II r$PE.qlf1t"iiO~$
I ·General specification.
1
•Power supply section specifications
Item Specification
--
--
Input
AC 220V ±10%, 50Hz
AC 240V ± 10%. 50Hz
Output
DC 12V
DC5V
*Specifications and design subject to change with-
out prior notice for product improvement. In
such
cases, items mentioned above may be
partially different from the product.
{CONSTITUTION OF SINGLE FLOPPY
•Constitution and Block Diagram
MZ-80SFD is constituted by floppy disk drive unit, control PWB unit, terminal resistor PWB unit and power supply
unit.
Its floppy disk drive is the same as the drives used for MZ-80FD/MZ-SOFDK/MZ-80FB/MZ.SOFBK.
[Power supply
circuit
Floppy disk drive Terminal resistor
PWB
r--
Control PWB
-
Block diagram
-1-

_O_P_E_R_AT_I_O_NA_L_PR_I_N_CI_P_LE_O_F_F_LO_P_P_···.·y_·.····O..:....-.' ........... $Kw...··· ••. >............... J
The floppy disk is designed to rotate the so-called
"diskette," amagnetic disk storage unit, to read out
and write in data at high speeds by bringing the
magnetic head
in direct contact witb aspecifil!d track
sector of 70 tracks formed in
both surfaces of the
diskette.
1. Fundamental block diagram
Drive
select
Read circuit
Write circuit
Operation (}--:":":'..,..-----""'1'---------.
. d' Write
In Icator ./ protect ,-!lr
/' senso!", IndeX~-'l'-- --'
0' ,/ sen_s~:JJJ'
-~~ ~ Head load-
Write
protectr"··" . actuator
la,*/' .,
)-1 I
1.-..--..----,...-' Index I~ ,I
Head select
Read
data
Write gate
Write
data
Write protect
Motor ON
..
Head select Head load • •
__ s_t_e;..p __ --.1,.......L--L--L..,I- ~. Rea1/write~""" • ..".
Direction •
Index
Motor ON ~d ~:I: \t==:INIJ.-1IlrJ
Track 00 '.
... ..,;D~r;;;;iv;.;.e;..s::.,;el;.;.e-ct--f Control circuit 1- __ -, Diskette
Head select
Motor
control circuit
2. Mechanism explanation
This device consists mainly of the following
mechanisms.
1) Read/write head
The head
is attached to the arm through aleaf
spring.
The head can follow the motion of
diskette easily.
Signals read
out of the head are transmitted
through FPC (Flexible Printed Cable) to the read
amp. circuit.
2) Carriage assembly
2units of read/write head are
mounted on the
carriage. The carriage is located with the stepping
motor and lead screw.
3) Head locating mechanism
This
is ahigh-precision, reliable head locating
mechanism using stepping
motor and screw-driven
ball/V-groove system.
The stepping motor is of 7.5°/pulse, steel plate
type.
One pulse of
step signal causes a2-step rotation
by 150,thus pushing forward the head by one
track.
41 Diskette driving mechanism
Asmall-sized
DC motor with tacho-generator is
employed. The motor rotation is transmitted
through the drive belt, spindle pulley and spindle
hub, thereby causing
rotation of the diskette. This
spindle pulley
is provided with astroboscope to
check rotation interval.
5) Head load mechanism
This
is amechanism in which the head is brought
into contact with the diskette. It is operated by
the head load actuator.
L..- ._~ . ~ __ ~ _
-2-

6) Write protect detection section
Aluminous diode and aphoto-transistor are used
to detect write
protect notch of the diskette and
jacket. (Writing
is not possible when the notch is
covered with labeL)
Center hole
Head
window
Label area
Index hole
Write
protect
notch
3. Interface
1) Interface signal
All lines are of TTL (transistor-transistor logic).
(1) Input signals
For input signals there are 10 kinds
of input lines,
all of which are valid at low levels. These signal
lines are terminated
at a150-ohm int~rated
resistor fitted in the IC socket of drive 1. The
signal voltage levels are
as follows.
High level IInvalid 2.4
to 5.25V
Low level IValid o
to OAV
Input impedance Pull-up
to 5V at 150-ohm
resistor
Description
of diskette parts
7) Index detection section
This section consists
of aluminous diode and a
phototransistor. An index hole
of the diskette is
detected by this section to determine the starting
point
of atrack.
8) Track 00 detection section
Acarriage position
is detected with alimit switch.
When
the carriage has reached the track 00 point,
track
00 signal is emitted.
9) Control electronics section
The electric circuit
to control each mechanism is
composed of 2sheets of PWB. One is to control
the
DC motor control circuit. The other is to
control other circuits, say, detection and other
functions with respect
to read/write, step, head
load, and
other signals.
10) Diskette protect mechanism
Shutting
the front door, with the diskette incom-
pletely set in, can give damage
to the diskette, thus
shortening its life-time.
To prevent such adraw-
back, this mechanism has been adopted so
that the
front door connot be closed if the diskette is
improperly in.
-3-
CD Drive select signals (0 to 3)
MZ-80SFD is connectable up to 4units.
These signals are used
to select adesired one of
the four drive units.
At low levels of drive select signal,
RIW head is
loaded to cause the operation indicator to light up.
Note)
The drive requires
to be set with adrive select
switch
to meet the position of use (Drive No. 1
thru 4).
@Motor ON signal
The drive motor starts when
the signal level be-
comes low. This signal level becomes high about
2seconds after completion
of all operations, if
no operation is commanded next. It thus inter-
rupts
the motor, extending the service life of
motor.
@Direction select signal
The signal
is given to designate the shifting
direction
of R
IW
head, when the step pulse is
input.
High level- - . Out direction (to diskette outer
portion)
Low
level - - - IN direction (to diskette center)
@Step signal
This signal
is given to move the RNoJ head in the
direction designated by the direction select signal.
The operation
is done in the course of changing
from low levels
to high levels.

®Write data signal
This signal
is used to write in data on the diskette.
Each time changing high levels
to low levels, the
current flowing in the RIW head is reversed to
write in data bit.
This write-in performance
is available when write
gate signal
is at low levels.
@Write gate signal
This signal being
at low levels, data can be written
on the diskette. At high levels, read-out or
sequential operation may be made.
(j) Side 1select signal
This signal
is given to decide which side of a
double-face
diskette to read or write. The RIW
head of side 0and that of side 1are selected at
high levels and low levels, respectively.
(2) Output signals
There are
the following four kinds of output signal.
CD Index signal
By this signal the. starting position of each track
can be detected. Each time
the index hole of
diskette is detected with the detector, the track is
fed from the drive unit.
Usually, this signal level becomes low each time
the hole
is detected at high levels. Therefore, the
leading edge
of the signal indicates the beginning
of atrack.
@Track 00 signal
The low-level state
of this signal signifies that
the RIW head is located at track 00 position (the
outermost trackJ.
In any position other than track DO, the signal is at
high levels.
When the RIW head is at track 00, the head is held
at the position by the stopper even if another
signal to step outside is given. At this time,
however,
the track 00 signal level becomes high.
By adding still
another signal to step outside, the
motor phase is returned to cause track 00 signal
to become low.
-4-
@Write protect signal
This signal
is used to detect whether or not write
protect for the diskette
is provided. When a
diskette with write
protect is in, the signal level
becomes low.
In usual operation, adiskette with write protect
enables to protect write statement within
the
drive.
.~ Read data signal
The signal
is given to transfer data read from the
diskette. Usually it
is at high levels, while during
detection it comes
down to low levels.

3) Timing
~\
-
-
-100ms MIN
--[
~~
I--Soons MAX
KOO
--
PRT
1000J,Ls MIN-
I
((
MAX--j
II
.... 1s
1/
~soons MAX
II
I-
Nu
II
1J,Ls
MI~ ~
--
~1tlsMIN
1J,LS
-MIN 4
-
1--1J,LS MIN
\
~~
~ .... - '---
t:::j
20ms
10ms
MIN MIN
{{
--
I}
1:=35m. MIN
1000tlsMIN --
- ..
100J,LS MIN
({
I1
II
SOms MIN
1sec MIN
--
-aJ,Ls MAX
"
II
'd
-~ if-
100J,Ls MIN
100J,Ls MIN-I--
--1
~ 3Sms MIN~ !--1000tlSMIN
\I
VALID
1I
VALID
50ms MIN \
~
VALID
1sec MIN
VALID
READ
DATA
WRITE
DATA
WRITE
GATE
SIDE ONE
SELECT
STEP
DRIVE
SELECT
VALID
INDEX
DIRECTIO
SELECT
DC POWER
MOTOR
ON
VALID TR
AND WRT
OUTPUT
Control and data timing
2) Power supply unit interface
Specified supply voltage of DC SV /DC 12V is fed from the power supply unit to the J2 connector of drive
control
PWB.
-S-

1. Belt
1) Inspeetion
Check
to see if the belt is stained with dust or dirt.
Also make sure
that there· is no unevenness,
scratch and thinned part.
2) Replacement
1) Take the belt off the spindle pulley while rotating
the pulley gradually by hand.
2) For applying the belt,
put the belt first on the
motor pulley and then on the spindle pulley while
rotating
the spindle pulley.
Note)
1. In putting on and off the belt, be careful so that it
be
not caught by the motor pulley flange.
2. Note
that there is no difference between both
sides of anew belt.
2. PWB unit
1) Replacement
1) Take connectors
J3 and J4 off PWB.
2) Remove 3 PWB unit fixing screws (3 mm).
3) Detach
PWB unit.
4) For reassembly, take the reverse order.
Note)
In replacing PWB unit, it is necessary to check
which short pins
to cut and whether or not
terminal resistor is required, depending on which
drive unit
to use (DRIVE No.).
•
Short pin: Detach the short pins from the old
PWB unit· and apply them to anew
PWB.
•Terminal resistor: If the old PWB unit has no
terminal resistor, remove terminal
resistor from anew
PWB.
J1 signa'
connector
J2 connector
(power)
,...--'0-----=--1 J3
connector
PWB unit
PWB unit fixing
screw (3 mm): 3pes.
J4 connector
~
Motor pullev
Keep belt
off the flange.
Socket
-6-

3. Index lamp assembly
1) Inspeetion
CD Connect power socket to connector J2 of PWB
unit. Turn power on.
® Make sure that there is avoltage range of DC 1 to
1.7V between B-11 (lower white lead of the 11th
pin from power socket) and A-11 (black lead of
the 11th pin from power socket), both belonging
to connector J3.
Note)
When attaching the index lamp assembly to the
carrier, fit the housing and LED in at the same
time.
-7-
2) Replacement
CD Remove PWB unit (refer to page 6).
®Disconnect 2lead wires of index lamp assembly
from the housing of connector J3.
@ Cut off the tie band fixing lead wires of index
lamp assembly (be careful not to damage lead
wires), and open the front door.
@) Take lead wires off the guide groove of carrier, and
draw out the index lamp assembly with tweezers
and fingers.
® To attach, take the reverse order.
®Carry out inspection, referring to description at
left.
Index lamp assembly
-0

4. Media guide lassembly (with write protect sensor lamp)
1) Inspection
ill Connect power socket to connector J2 of PWB
unit. Turn power on.
@Before inserting adiskette, check the following
items.
a) Write protect lamp
Make sure that there is avoltage range of DC 1
to 1.7V between B-13 (lower yellow lead of the
13th pin from power socket) and A-13 (black
lead of the 13th pin from power socket), both
belonging to connector J3.
b) Write protect sensor
Make sure that there is avoltage range of DC 0
to O.5V between B-14 (orange lead below the
14th pin from power socket) and A-14 (black
lead of the 14th pin from power socket), both
belonging to connector J3.
@Put awrite protect diskette (with write protect
seal being applied at the write protect notch of
diskette) in place, and shut the front door. Then
check the following item.
•Write protect sensor
Make sure that there is avoltage range of DC
2.5 to 5.25V between 8-14 and A-14 of
connector J3.
2) Replacement
CD Remove PWB unit (refer to page 6).
@Open the front door.
@Detach 4lead wires of media guide Lassembly
from the housing of connector J3.
@Remove 2media guide Lassembly fixing screws
(3 mm) and take out the assembly.
@To attach, take the reverse order.
®Carry out inspection, referring to description at
left.
Note)
1. Attach the media guide Lassembly by pushing it
to main frame stopper side and front bezel side.
2. Lamp and sensor cannot be individually replaced,
because they are built in the media guide L
assembly.
Media guide Lassembly fixing screw
Push
Media
guide L assembly
Write protect lamp
Front bezel
Main
frame stopper
-8-

5. Operation indicator
1) Inspection
CD Connect power socket to connector J2 of PWB
unit and turn power on.
(Z; Let drive select 0 of interface signals be at low
levels (make ashort between J1·B terminal
of PWB
and PWB Ground). and make short pin DSO
circuit shorted. (Do not prolong this test.)
Note
that the voltage range between connector
J3·B10 (red lead of
the 10th pin from power
socket) and J
3-A 10 (upper black lead of the 10th
pin from power socektl will be
DC 1 to 2V when
the lamp
is lit.
2) Replacement
CD Remove PWB unit (refer to page 14).
@Datach 2lead wires of operation indicator from
the housing of connector J3, and take lead wires
out of the wire holder.
CID Open the front door.
@) Remove 2front bezel fixing screws (3 mm) and
the front bezel itself by pulling it forward.
@) Draw out the holder 2with tweezers in the arrow
direction. Take
out LED holder. (See the sketch at
right.)
@Draw LED out of the LED holder. To assemble,
take the reverse order. .
(j) Carry out inspection, referring to the above
instruction.
Front bezel
LED holder
Pull-out direction
Note:
1. Attach the front bezel assembly, by pushing it to
main frame side and main frame stopper. (See the
sketch below.)
2. Do not pull up the carrier with fingers, otherwise
excessive force
is applied to the head arm.
Main frame side
Front bezel
Front door
-9-
1)'
Push
Main frame stopper
Main frame side
Front bezel fixing screw

6. Drive motor assembly IDe mOlor and mOlor cortl.al PV/e unill
11 Inspection
<!> Connect _ >ocr.., '0 cannectot n of PWB
"";t. T .... __ Oft.
(%ll.ed in, .. face mol .. ON .i!lnols be a, low ....e/s
lmab .01'> ... bel',,"" JI·16 l...... iNf 0' PW8 uni,
_ PW8 Groundl and run tIM mol ... 100 .... ,
prolong ,his ,-.1
<]) Pul. dish". In p1_ and clme 1M I<on, <100<.
@ amy on hod load.
(8) Make .ur. '11" III. moboplate attaclled on IIII'
• pindl. pulley .ppo ... 10 be .tationary.
Note)
The oIIiftiflll ,ata olwol>oplale is allowflj to be ""
to 1.5 pc;..M.
V .. _-",_
I"'" __ ... _01
...... _' ......... 6 .....
No••l
In mOlJnlI~ 'III' DC mOlD'. til. dl.tl~ bet,veon
.pl""I. pull.y and mOtor pulley .hould be kept to
be 73 .iOA mm "' III<Iwn abo ••.
_10_
21 Rtplocemonl
<D R .... .- PWB ""il. CR.' ... to pogo 6.1
<2> Put off 1M bfoIl. lR,I .. 10 _ 6,1
<:p Cu. olf tIM ,iI bind I .. fi ..... Iud wi ... of ......t ..
_ mol<>< eont..... fIWB unit. lk _,lui nol to
d ..... lead .....
<!> A_ 3 Iud .ir .. ......,..,.'" t...... tM motor
<:on1r01 P\W u 10 conntlC<Of JJ_lrom 1M I>ooJs.
ing of """"oct J3.
tID R.m"". 2 met tontrol PWB Unil fixing ocrew.
13
mml ar>d 2 DC motor fixing OC'I'WO 13 mml .
Ootacll the DC meto, and molD' oontrel PWB unit
'rom Ih. mlin frame.
@} For auernbly. tak. tho ,,,,,er. ord.,.
CV Catty cu, insI>ection. ,.,.ttinll to ....."iption al
"".
3f Adju.'mon,
Q) Alto, ,h. cOmpletion of th. lbo •• chock ilom •.
Idiu" the ... ilbl. , •• i"", 0' molD! controf PWB
unit '" ,hal '1>0 ltroboplat. appe_l 10 be tom·
p1llely Ilatio"",y

[ TROUBLE SHOOTING GUIDE
Start of disk system
of
error message. (See page 12.1
Trace the cause from the contents
Yes
Yes
Check repair procedure for power
~--------'~ supply section.
(See pages 13 and
14.1
No
End
•Check by replacing several sheets of diskette to see if errors occur due to faulty diskette (data deterioration
caused by foreign matters, deformation, wear-out, damage, magnetism, etc.).
•Troubles
in disk system often cause error messages. Trace the cause from the contents of error message.
•Replace suspected parts
in the disk system with normal ones. Check again the trouble section.
1) Personal computer
2) Interface unit or expansion port
3) I/O card
4) Diskette
5) Signal cable
6) Disk drive
•The signal circuits of floppy disk and I/O card operate at TTL levels of
OV, +5V. Connect any system other than
micro-computer peripheral devices for MZ-80 series
to see if signal levels are out of the range of 0 to +5V (max.
+5.25V).
•The disk drive needs a RAM area of more 36K bytes. If the RAM area of your machine is less than 36K bytes,
it must be expanded.
-11-

•Error chart for disk system
Error code
[Error message] Contents Check item and corrective action
50
1) Drive fails to be ready.
[NO READY] aDiskette is wrongly inserted. aFit diskette in correctly.
aMotor does not normally run. aCheck belt and/or drive
motor assembly.
aIndex detection circuit is improper. aCheck index lamp, drive
PWB, index sensor.
aFlat cable is improperly fit in or broken. aCheck flat cable.
a No select signal comes at drive. aCheck floppy disk I/O card.
aDrive unit door (front door) is not
aClose front door.
closed.
aDiskette is faulty. aReplace diskette.
aWrite operation is attempted in write
protect state.
54
1) Drive
[UNFORMAT] aHead position is not aligned. aReplace drive unit.
(off-track state)
aHead and amp. circuit are defective. aReplace drive unit and/or drive PWB unit.
2) Diskette
aDiskette not formatted is in use. oInitialize again, or replace diskette
aCRC error in 10 field.
a10 field is broken down.
41
1) Drive
[DISK DATA aSEEK error aCheck drive unit and diskette
ERROR] Replace,
if required.
aHead shift is improper. aReplace drive unit.
2) Diskette
aCRC error in data field.
aData field is broken down.
iO Initialize again, or replace diskette.
a10 field is defective.
aData mark detection error.
-12-

! POWER supplv SEcnON
Block Diagram of Power Supply Section
v
v
.---
..---
..
+12
Gl
~
ERectifying
and
Transistor
'-'
..
..
AC
Gl
~
Chopping
~
Smoothing
INPUT LL
I--
cCircuit Circuit
..
t--
'-F
..
...
"--
:......-
Control
Circuit
1G
~
...-<>
Transistor
+5
'"'-
Rectifying and Chopping
Somoothing Circuit
'---
Circuit
~
Control
Circuit
1
Waveform of Each Part
Waveform of pin@ of IC201
and pin (5) of IC301. Waveform
of pin ([j) of IC201. Q202 collector waveform.
I
22V
/-22~s-i
40~s~
22V
24~s
4(j~s
Waveform of pin ([j) of IC301.
0302 collector waveform.
15V
15~s
40~s
-13-

• Trouble Shooting Chart
Problem 1: No voltage appears at any output terminal.
~
Check AC COrdi
AC socket, F101, F102
Is there AC 220V (240V
AC switch and C101.
for U.K.I present across
C101?
V~
Check n01
Problem 2: +12V is not developed.
~
Check IC201 and its
peripheral
parts.
r---
Is there AC 20V
present across the
V;:
Check output switching
red lead
of n01 7circuit.
Leave R203 be open;
~
Nrl
N~
does there appear
f---
Check n01.
Check 0201
1Vp-p pulse at pin
No.
11 of IC201.
I.-
V~
Is there DC 20V
present across
C2027
.--
Does waveform of the
V~
chart appear in
~V~
collector of Q2027
Check L201 and
C205,C209.
Problem 4: +5V is not developed.
No Check IC301
and its
~
peripheral parts.
r-
Is there AC 14V
present across the
Check output
yellow lead of T101 7Yes switching circuit.
Leave R303 be open;
~
nNo does
there appear
f--
Check n01.
r-t
Check 0301.
1Vp-p pulse at pin
No.
11 of IC301.
L-
Is there DC 14V
V~
f--
present across C302?
Does waveform of the
V~
chart appear in collector
t---
of 03027
Check L301, C305.
Yes
and C309, C310.
-14-

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... ...
o
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~
eN
~
....
Parts marked with "& " are important for maintaining
the safety of the set. Be sure to replace these parts with
specified ones for maintaining
the safety and perfor-
mance
of the set,
m
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• Power Supply PWB
Primary
7
8
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10
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Secondary
-16-
F0410PA

A B cDE F G.
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1•Disk Drive
PWB Circuit (Reference diagram)
STEPPING
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10 3~ 11 10 3C 8 TOO iA23 LS123 L . -C''!W~P:'I.l'-'2,i2"'' JfI I
'-----0 R1S , 9 lSOo/ 820 10;;c::~;2~EJ' ... 2-.:9q' 8r ----:},"'-'~,~U2~AJ-~I~I~J,,'..:-2"'8'-? WRITE
TRACK 00 I 680 All lS14"'" j l.-<=-r!.rl 399';;'1_+____i~-+____i~r---!.!(I~R'"D'.:'V~I____i~+_+-+__+-_, IDS 13 38 'r:; I PROTECT
SWITCH J3-A9 680 r "'1..505
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NC ·---·~~·__nk~81r4 13 11 -+5V -"~~-1 (PAd 8I IN USE LED
I ~ IrI I l'I'~!--!l-.l",'C~' 10 (TOO~ (TOO) 2
150 Ii AN6 i i i IRN4 9 LSoy- -·--+-+---"-IS·T-CE"P..J j PS R15 +SV (rpO) -t-----+-------"~¢.".." '-' ..!,-U3~E_\.?3'--"'J1'--"'-~ TRACK 00
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1.
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1Jl-4 HL ~,-. ------ -_. -_t__t_--. I y-. 45
0
1
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HM _--=--3
q"4
:-_++_---'9'j".§,~8'-.-r-+-----+---+::.IM::.O:.T:..0:.R-=-=D::.N:..:)+--+--+-----' IR 2 38 INDEX
J'-32 .... c_ .... ,A_ '--+--. e q,~
0-=-' .. --. -j H HI' , sr---.. 6v LS04 V01 (IDS' (IDSI"
8 ,~ ,,,)(;.... >-f-t-+-----------, ]------=--'-'--- --+-----j--t----=--='------t--t--+.----j------t--==----t ~9~"", 8 R
I0 ~~~=~~;>=j~V,~L~S~0~4 HS +--+--I--;2~f;;:, S 2 (INDEX I 1-_~L...:R~~U2~A:J)--{-J 0,--",J,,,,-3,,4,--0
DRIVE SELECT I! rD::~ ~ 2
LG 500
It;o- 10 ~ 3 ~~02 ~ ~~_O_} 4 1~~~~'o/"'3'--1-t-!_-+--+-_ .. ''':H<lL11---1.--_+____I, 10 38
o0 Jl·lO ------t_-i!-e J LS05 RN4 .+~V ~5V 13 10 6 15 {AOY) +12V..,-L_--;= r_"J"'3-"'B,,4-,,----,
I Jl-l2 OSl 3 -- 1 T4 - 1 . c---':'=:--'c~-- .. --;",~~:!-;;--, .--+--+---+-+--+---'-'-"=.:..'---1----' -'
, Q---"-'---- .. "-~-- -+---e: RN6 2__ +5V WS/RS PR INDEX 1>0 8 L_.!.'"IR"'D"-V'-I'--t ---=-'I;C 3Dl~ ........ ' 1 I
20
1 Jl·14 DS2, .~'~:::i¥-'J I MX. L-: :J RDY r-"" J3-A4
tj
-I 4.1K 1 ~ 2RN4 4.7K 317 lHU 2 452
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3 0
0
---"-=--------' 150 iWGl ,/ LS04 4""I--'-=6'----:c+ ----'11+SV -r-+5V C16
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8 9 1 twO) 5v
18T+
5V
R10 -r_ R13 "l 5 2A Jl·3Q
18 ~;~~-I----''t-''-=21---~1''-°hl rC;jRN4 I -- -+---'·E-G-'-----,,·-----------"-!WD 20 cc 9T_
C15
18K 15 14
22
;;: 9.1K
76
,rml-~3~gU~-'.='--1AEAD DATA
1i0I I i4.7K .... _._...:::~ '-=14 EG GND O.Oli-! 1;'3:.2.....
150t.:f---::f--c3 :f--::'I'--'150 5I DR/2STE~TEP CP DLIRD RM 7l1r- LS123 LS123
O
Jl-24 76 5 1 '30 2----..l 38 1 2 11 7 121 210
388'r-n-r-2
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LS14 _ 13 LSD VLS'f4 .Jr. 3
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I a.olp x4
3
4
2
5
6
7
8
9
10
11
-17-
-18-

ABcDE F GH
1•Disk Drive PWB (Reference diagram)
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2
3
4
5
6
7
B
9
10
Penpective View
[::=I Parts·fitted face
c=J Opposite side
11
-19-