NEC FD1165 User manual

F Dl 165
Flexible Disk Drive
Maintenance Manual
SEC
NEC Info rm ation System s. In c.
819-000090-2001
10-82

LIABILITY DISCLAIMER
NEC Information Syst ms, Inc. products ar warrant d in
accordanc with th t rms of th applicabl NEC Information
Syst ms, Inc. product sp cification. Product p rformanc
is aff ct d by syst m configuration, softwar , th applica
tion, custom r data and op rator control of th syst m among
oth r factors. Whil NECIS products ar consid r d to b
compatibl with most syst ms, th sp cific functional impl 
m ntation by custom rs of th product may vary.
Th r for , th suitability of a product for a sp cific
application must b d t rmin d by th custom r and is not
warrant d by NECIS.
This manual is as compl t and factual as possibl at th
tim of printing, how v r, th information in this manual
may hav b n updat d sinc that tim . NEC Information
Syst ms, Inc. r s rv s th right to chang th functions,
f atur s, or sp cifications of its products at any tim ,
without notic .
NEC Information Syst ms, Inc. has pr par d this docum nt for
us by NECIS mploy s and custom rs. Th information con
tain d h r in is th prop rty of NECIS and shall not b r 
produc d in whol or in part without prior writt n approval
from NECIS.
First Printing - Octob r 1982
Copyright 1982®
NEC Information Syst ms, Inc.
5 Militia Driv
L xington, MA 02173
Print d in U.S.A.

FEDERAL COMMUNICATIONS COMMISSION RADIO FREQUENCY
INTERFERENCE STATEMENT
Although disk driv s as subsyst m typ compon nts do not
r quir FCC rating, th following stat m nt appli s to th
Mod l FD1165.
This unit has b n typ t st d and found to comply with th
limits for a Class B computing d vic in accordanc with th
sp cifications for Subpart J of Part 15 of FCC Rul s, which
ar d sign d to provid r asonabl prot ction against such
int rf r nc in a r sid ntial installation.
Manufactur r's Instructions and Us r's R sponsibiliti s
to Pr v nt Radio Fr qu ncy Int rf r nc
Manufactur r's Instructions
Th us r must obs rv th following pr cautions in install
ing and op rating this d vic :
1. Op rat th quipm nt in strict accordanc with th
manufactur r's instructions for th mod l.
2. Ensur that th unit is plugg d into a prop rly
ground d wall outl t and that th pow r^ cord sup
pli d with th unit is us d and not modifi d.
3. Ensur that th unit is always op rat d with th
factory install d cov r s t on th unit.
4. Mak no modification to th quipm nt which would
aff ct its m ting th sp cifi d limits of th
Rul s.
5. Prop rly maintain th quipm nt in a satisfactory
stat of r pair.

Us r's R sponsibility
Th us r has th ultimat r sponsibility to corr ct probl ms
arising from harmful radio-fr qu ncy missions from quip
m nt und r his control. If this quipm nt do s caus int r
f r nc to radio or t l vision r c ption, which can b
d t rmin d by turning th quipm nt off and on, th us r is
ncourag d to try to corr ct th int rf r nc by on of th
following m asur s. All of th s r sponsibiliti s and any
oth rs not m ntion d ar xclusiv ly at th xp ns of th
us r.
1. Chang in ori ntation of th r c iving d vic
ant nna.
2. Chang in ori ntation of th quipm nt.
3. Chang in location of quipm nt.
4. Chang in quipm nt pow r sourc .
If th s att mpts ar unsucc ssful, install on or all of
th following d vic s:
1. Lin isolation transform rs
2. Lin filt rs
3. El ctro-magn tic shi lding
If n c ssary, th us r should consult th d al r, NEC or an
xp ri nc d radio/t l vision t chnician for additional sug
g stions. Th us r may find th following bookl t pr par d
by th F d ral Communications Commission to b h lpful; "How
to Id ntify and R solv Radio-TV Int rf r nc Probl ms."
This bookl t is availabl from th U.S. Gov rnm nt Printing
Offic , Washington, D.C. 20402, Stock No. 004-000-00345-5.
"Not : Th op rator of a computing d vic may b r quir d
to stop op rating his d vic upon finding that th d vic
is causing harmful int rf r nc and it is in th public
int r st to stop op ration until th int rf r nc probl m
has b n corr ct d."
i v

CONTENTS
Pag
1.1 DESCRIPTION................................... 1-1
1.2 CONSTRUCTION AND FEATURES . .................... 1-2
1.2.1 Bas Fram ...... .................... 1-2
1.2.2 Spindl Ass mbly .................... 1-2
1.2.3 Dc Dir ct Driv Spindl Motor ....... 1-3
1.2.4 Carriag R ad/Writ Ass mbly H ads... 1-3
1.2.5 St pping Motor ....... . ............... 1-3
1.2.6 H ad Load Cam Ass mbly.......... 1-3
1.2.7 Pop-Up F atur .. .................... 1-4
1.2.8 Ind x S nsor........ ................ 1-4
1.2.9 00 Track S nsor............ 1-4
1.2.10 Writ Prot ct S nsor ................ 1-4
1.2.11 M dia-In S nsor. .................... 1-4
1.2.12 Coll t Ass mbly. .................... 1-4
1.2.13 Print d Circuit Board (PCB).......... 1-4
1.2.14 Variabl Fr qu ncy Oscillator
(Optional) . ........... 1-4
1.2.15 Display Lamps... .................... 1-5
1.2.16 Front Pan l............ ............. 1-5
1.2.17 Movabl Door Handl ................. 1-5
1.2.18 Door Lock Sol noid .................. 1-5
1.3 SPECIFICATIONS.......... 1-5
CHAPTER 1 GENERAL INFORMATION
CHAPTER 2 INSTALLATION AND OPERATION
2.1 PRELIMINARY INSPECTION... .................... 2-1
2.2 UNPACKING AND REPACKING ...................... 2-1
2.2.1 Unpacking Proc dur .................. 2-1
2.2.2 R packing Proc dur .................. 2-1
2.2.3 Pr installation Insp ction .......... 2-3
2.3 ENVIRONMENTAL REQUIREMENTS ................... 2-3
2.3.1 Op rating Environm nt................ 2-3
2.3.2 Spac and W ight Data ............... 2-3
2.3.3 Mounting ............................ 2-3
v

CONTENTS (cont’d)
2.4 POWER SUPPLY ................................. 2-6
2.4.1 Pow r Supply Sp cifications ......... 2-6
2.4.2 Pow r Conn ctor ..................... 2-6
2.4.3 Pow r Conn ctor Pin Assignm nts ..... 2-7
2.5 INTERFACE CONNECTION ......................... 2-8
2.6 TERMINATOR RESISTORS ......................... 2-9
2.7 DRIVE IDENTIFICATION (DX) SELECTION .......... 2-12
2.8 OPTION SELECTION ................... 2-12
2.8.1 H ad Load Jump r (HL) ............... 2-12
2.8.2 Radial R ady Jump r (RX) ............ 2-12
2.8.3 Sid S l ct Jump r (SS) ............. 2-12
2.8.4 Writ Prot ct Jump r (PR) ........... 2-13
2.8.5 Fil Unsaf Jump r (FR) ............. 2-13
2.8.6 Door Lock Jump rs (DL, DR, DH) ...... 2-13
2.8.6.1 DR Jump r .......................... 2-13
2.8.6.2 DL Jump r ........................... 2-13
2.8.6.3 DH Jump r .......................... 2-13
2.8.7 In Us Pins (US) .................... 2-14
2.8.8 R ad Data Pins (RD) ................. 2-14
2.8.9 Busy Lamp Jump rs (BU, BS) .......... 2-14
2.8.9.1 Busy Lamp On During H ad Load ...... 2-14
2.8.9.2 Busy Lamp On During Driv S l ct ... 2-15
2.8.9.3 Busy Lamp On During In Us ......... 2-15
2.9 OPERATING THE FD1165 ......................... 2-15
2.9.1 Ins rting a Fl xibl Disk ........... 2-15
2.9.2 R moving a Fl xibl Disk ............ 2-16
2.10 DISPLAY LAMPS............................. 2-16
2.10.1 R ady Lamp .......................... 2-16
2.10.2 Busy Lamp.............. 2-17
Pag
vi

CONTENTS (cont’d)
CHAPTER 3 INTERFACE INFORMATION
3.1 BASIC OPERATIONAL DESCRIPTION... ............. 3-1
3.2 ELECTRICAL INTERFACE ......................... 3-2
3.2.1 Signal L v ls ....................... 3-2
3.2.2 Driv r/R c iv r Circuits ............ 3-2
3.2.3 Int rfac Lin s ..................... 3-3
3.3 INPUT SIGNALS .......... ...................... 3-3
3.3.1 Driv S l ct 1 Through 4 (DSX1 to 4). 3-3
3.3.2 H ad Load (HDL) . ..................... 3-4
3.3.3 St p (STP) .... ...................... 3-4
3.3.4 Dir ction S l ct (DIR) .............. 3-4
3.3.5 Sid S l ct (SSL) ................... 3-4
3.3.6 Writ Gat (WGT) .................... 3-5
3.3.7 Writ Data (WDT) .................... 3-5
3.3.8 Low Writ Curr nt (LWC) ............. 3-5
3.3.9 Fil Unsaf R s t (FUR) ............. 3-6
3.3.10 InUs (USE).... .................... 3-6
3.4 OUTPUT SIGNALS ......... ...................... 3-6
3.4.1 Ind x (IDX) ......................... 3-6
3.4.2 Track 00 (TKO) . . ..................... 3-7
3.4.3 Dual-Sid d (TSD) .................... 3-7
3.4.4 R ady (RDY) ... ...................... 3-7
3.4.5 Fil Unsaf (FUS) ................... 3-7
3.4.6 R ad Data (RDT) . ..................... 3-8
3.4.7 Writ Prot ct (PRT) ................. 3-8
3.4.8 Disk Chang (DCG) ................... 3-8
3.5 VFO INTERFACE SIGNALS ........................ 3-9
3.5.1 Modifi d Fr qu ncy Modulation Mod
(MFM) ............................... 3-9
3.5.2 VFO Synchronization (SYC) ........... 3-9
3.5.3 Standardiz d R ad Data (SRD) ........ 3-9
3.5.4 Window (WID) ........................ 3-9
3.6 INTERFACE TIMING..................... 3-10
3.6.1 Pow r On S qu nc ................... 3-10
3.6.2 Driv S l ct ........................ 3-10
3.6.3 St p and Track 00 ................... 3-10
3.6.4 Acc ss .............................. 3-11
3.6.5 Writ ....................... 3-11
3.6.6 R ad ................................ 3-12
Pag
vii

CONTENTS (cont’d)
CHAPTER 4 MAINTENANCE
4.1 PREVENTIVE MAINTENANCE......................... 4-1
4.2 MAINTENANCE TOOLS . ............................. 4-1
4.3 MAINTENANCE PARTS.............................. 4-1
4.4 REMOVAL AND REPLACEMENT PROCEDURES .............. 4-2
4.4.1 PCB R moval ........ ............... 4-2
4.4.2 Coll t Ass mbly R moval, R plac m nt,
and Adjustm nt ......... . ......... . 4-3
4.4.3 Carriag Ass mbly R moval and
R plac m nt........................... 4-6
4.4.4 H ad Load Cam Ass mbly and H ad Load
Cam R moval and R plac m nt ........... 4-8
4.4.5 Writ Prot ct S nsor and M dia-In
S nsor R moval and R plac m nt ......... 4-9
4.4.6 Optical Tachom t r S nsor R moval
and R plac m nt............... 4-10
4.4.7 S nsor Cabl Ass mbly (LED Ass mbly
and Ind x S nsor R moval and
R plac m nt ......................... 4-11
4.4.8 R moving and R placing th Carbon
Brush s ............................. 4-14
4.4.9 Armatur R moval .................. ... 4-15
4.4.10 Spindl Ass mbly R moval ............ 4-16
4.4.11 Front Pan l R moval............ 4-17
4.4.12 Pick r Rod R moval and R plac m nt... 4-17
4.4.13 Pop-Up Ass mbly R moval and
R plac m nt ......................... 4-18
4.4.14 Guid Rail R moval .................. 4-19
4.4.15 Ch cking th Op ration of th Pop-Up
F atur ............................. 4-19
4.4.16 Door Lock Sol noid R moval and
R plac m nt ......................... 4-20
CHAPTER 5 ADJUSTMENTS
5.1 DIAGNOSTIC TESTS............................... 5-1
5.1.1 Auto Tap T st......................... 5-2
5.1.2 Auto S k T st........................ 5-2
5.1.3 Auto S k and Auto Tap T st ............ 5-2
5.2 HEAD UNLOAD DELAY.............................. 5-2
5.3 TEST POINTS.................................... 5-3
Pag
viii

CONTENTS (cont’d)
Pag
5*4 ADJUSTMENTS AND CHECKS USING THE ALIGNMENT
FLEXIBLE DISK. . ........... * ............... . 5-3
5.4.1 H ad Radial Alignm nt Ch ck or
Adjustm nt ...... . .................... 5-4
5.4.2 Azimuth Ch ck. ...................... 5-6
5.4<3 Ind x Alignm nt Ch ck or Adjustm nt.. 5-7
5.5 OTHER ADJUSTMENTS . . ........................... 5-8
5.5.1 LED Ass mbly/Ind x Ass mbly Ch ck
and Adjustm nt..*........ ........... 5-8
5.5.2 00 Track S nsor Ch ck or Adjustm nt.. 5-9
5.5.3 Writ Prot ct S nsor Ch ck or
Adjustm nt..................... 5-10
5.5.4 H ad Load Ch ck ..................... 5-10
5.6 TRIM POTS .... . ........ 5-11
CHAPTER 6 ILLUSTRATED PARTS BREAKDOWN
CHAPTER 7 SCHEMATIC
ix

LLUSTRAT ONS
Figur Titl Pag
1- 1 FD1165 Fl xibl Disk Driv ................. 1-2
2- 1 Unpacking .................................. 2-2
2-2 Mod l FD1165 Physical Dim nsions ........... 2-4
2-3 V rtical Installation ...................... 2-4
2-4 Horizontal Installation .................... 2-4
2-5 On-End Installation ........................ 2-5
2-6 Air Flow R quir m nts for Natural Air
Cooling .................. ................. 2-5
2-7 Pow r Conn ctor Location ................... 2-7
2-8 Pin and Lin Assignm nts for th Pow r
Conn ctor .................................. 2-7
2-9 Contact Arrang m nt for Edg Conn ctor ..... 2-8
2-10 Int rfac Conn ctor ........................ 2-8
2-11 T rminator R sistors and Jump r Locations
on th PCB ................................. 2-10
2-12 Parall l and S ri s Configurations ......... 2-11
2-13 Closing th Door of th FD1165 ............. 2-15
2- 14 Unlocking th Door and R moving th
Fl xibl Disk ................ . ............. 2-16
3- 1 Driv r/R c iv r Circuits ................... 3-2
3-2 Int rfac Lin s ............................ 3-3
3-3 St p Signal Timing ......................... 3-4
3-4 WGT Timing ................................. 3-5
3-5 Writ Data Signal Timing. .................. 3-6
3-6 Ind x Signal Timing .... . .................. 3-6
3-7 R ad Data Signal Timing .................... 3-8
3-8 Disk Chang Signal Timing .................. 3-9
3-9 R ad Data and Window Signal Timing ......... 3-10
3-10 St p and Track 00 Timing ................... 3-10
3-11 Acc ss Timing .............................. 3-11
3-12 Writ Timing ............................... 3-11
3- 13 R ad Timing ................................ 3-12
4- 1 R moving th Coll t Ass mbly ............... 4-3
4-2 R placing th Coll t Ass mbly .............. 4-4
4-3 H ad Unload Spring in R lation to Spring
Plat ...................................... 4-5
4-4 Position of th Spring Plat ............... 4-5
4-5 Carriag Ass mbly Position on th Bas Fram 4-7
4-6 R moving th H ad Load Cam .... ............. 4-8
4-7 Installing th H ad Load Cam Ass mbly ...... 4-9
4-8 Writ Prot ct or M dia-In S nsor
Conn ctions ................................ 4-10
4-9 Installing th Writ Prot ct or M dia-In
S nsor..................................... 4-10
4-10 R moving th R placing th Optical
Tachom t r S nsor .......................... 4-11
x

LLUSTRAT ONS (cont’d)
Figur Titl Pag
4-11 R moving th S nsor Cabl Ass mbly ......... 4-12
4-12 Installing th Ind x S nsor ................ 4-13
4-13 R moving a Carbon Brush .................... 4-14
4-14 R moving th Armatur .. .................... 4-15
4-15 R moving th Spindl Ass mbly .............. 4-16
4-16 R moving th Front Pan l ............ ....... 4-17
4-17 Adjusting th Pick r Rod ................... 4-18
4-18 R moving th Pop-Up Ass mbly and Guid Rail. 4-19
4-19 R moving th Door Lock Sol noid ............ 4-20
4- 20 Adjusting th Door Lock Sol noid ........... 4-21
5- 1 Location of Diagnostic T st Pins and T st
Points ................................. . 5-1
5-2 H ad Radial Alignm nt Wav form ............. 5-5
5-3 Adjusting H ad Radial Alignm nt ............ 5-6
5-4 Azimuth Wav form ........................... 5-7
5-5 Ind x Alignm nt Wav form.................... 5-8
5-6 Wav forms at TP7 and TP10 .................. 5-9
5-7 Track 00 Signal. ....... .................. 5-9
5- 8 H ad Load Wav form ......................... 5-11
6- 1 FD1165 Fl xibl Disk Driv .................. 6-5
6-2 G9NYF PCB Ass mbly ......................... 6-7
TABLES
Tabl Titl Pag
1- 1 FD1165 Sp cifications ........................ 1-5
2- 1 Pow r Supply Sp cifications .................. 2-6
2-2 Pow r Conn ctor Part Numb r .................. 2-6
2-3 Data and Control Int rfac Contact
Assignm nts ................................ 2-9
2-4 Door Lock Jump r Combinations .............. 2-14
4-1 Maint nanc Tools ............................ 4-1
4- 2 Maint nanc Parts ............................ 4-2
5- 1 T st Points and Signals ...................... 5-3
5-2 Adjustm nts .................................. 5-3
5-3 H ad Radial Alignm nt Oscilloscop S ttings. 5-4
5-4 H ad Azimuth Oscilloscop S ttings ........... 5-6
5- 5 Ind x Alignm nt Oscilloscop S ttings ........ 5-7
6- 1 List of Illustrations ........................ 6-3
xi

L ST OF ABBREV AT ONS
A Amp r
DIR Dir ction S l ct
DCG Disk Chang
DLH Door Lock Hold
DSX Driv S l ct
FDD Fl xibl Disk Driv
FM Fr qu ncy Modulation
FUR Fil Unsaf R s t
FUS Fil Unsaf
HLD H ad Load
IC Int grat d Circuit
IDX Ind x
I/O Input/Output
k 1000
kg Kilogram
LED Light Emitting Diod
LSI Larg -Scal Int gration
LWC Low Writ Curr nt
mA Milliamp r
MB M gabyt
MFM Modifi d Fr qu ncy Modulation
ms Millis cond
mV Millivolt
PCB Print d Circuit Board
POH Pow r-On-Hours
pp P ak-To-P ak
PRT Writ Prot ct
RDT R ad Data
RDY R ady
rpm r volutions p r minut
SRD Standardiz d R ad Data
SSL Sid S l ct
STP S t p
SYC Synchronization
TKO Track 00
TSD Two-Sid d Disk
TTL Transistor Transistor Logic
USE In Us
Vdc Volts dir ct curr nt
VFO Variabl Fr qu ncy Oscillator
WDT Writ Data
WGT Writ Gat
WID Window
ys Micros cond

CHAPTER 1
GENERAL NFORMAT ON
This chapt r giv s an ov rall d scription of th Mod l
FD1165 8-Inch Fl xibl Disk Driv , d scrib s th f atur s
and parts of th disk driv in d tail, and lists th sp ci
fications .
1.1 DESCRIPTION
Th Mod l FD1165 Fl xibl Disk Driv is a compact magn tic
disk storag d vic that us s singl - or dual-sid d, singl -
or doubl -d nsity fl xibl disks. Th storag capacity of
th disk driv d p nds on th typ and format of th disk
tt that is us d. With a dual-sid d fl xibl disk and a
doubl -d nsity format, th maximum-storag capacity is 1.6
million byt s (MB).
Th most appar nt f atur s of th Mod l FD1165 ar its small
siz and light w ight. Th disk driv m asur s 8.55 inch s
(217.2 mm) high, by 2.28 inch s (58.0 mm) wid by 13.20
inch s (335.0 mm) d p and w ighs only 7.7 pounds (3.5 kg).
Th disk driv has all th f atur s and p rformanc of
larg r, conv ntional units, and is m dia-compatibl and
int rfac -compatibl with t;h m. B caus th Mod l FD1165
m asur s on -half th h ight of conv ntional disk driv s,
two disk driv s can b mount d in th sam spac as on
conv ntional driv .
Th Mod l FD1165 is op rat d by an xt rnal controll r (NEC
yPD765 is r comm nd d) through a Transistor Transistor Logic
(TTL) int rfac . Th disk driv r quir s an xt rnal pow r
supply that must supply and control two voltag s, +5 Vdc
(for th TTL) and +24 Vdc (for th dc dir ct driv spindl
motor) (s S ction 1.2.3). Th disk driv f atur s a
microproc ssor-controll d h ad loading m chanism that mini
miz s h ad and m dia w ar. Th h ad position m chanism
(st pping motor) is also microproc ssor-controll d to nsur
xtr m ly accurat h ad positioning.
1-1

1.2 CONSTRUCTION AND FEATURES
This s ction d scrib s th construction of th Mod l FD1165
and xplains th f atur s of th various ass mbli s. S
Figur 1-1 to id ntify th ass mbli s that ar d scrib d in
this s ction.
Figur 1-1 FD1165 Fl xibl Disk Driv
1.2.1 Bas Fram
Th bas fram is th m tal form that supports th sub-
ass mbli s of th disk driv .
1.2.2 Spindl Ass mbly
Th spindl ass mbly supports th fl xibl disk in th disk
driv and rotat s th fl xibl disk at 360 r volutions p r
minut (rpm).
1-2

1.2.3 Dc Dir ct Driv Spindl Motor
Th dc dir ct driv motor (not shown) rotat s th spindl
ass mbly. This dc motor liminat s th probl ms that ar
associat d with conv ntional ac motor driv s.
• Th motor do s not us driv pull ys or b lts, lim
inating th probl ms associat d with th s parts.
• Th motor consum s l ss pow r than conv ntional ac
motors. Low-pow r, in xp nsiv pow r suppli s can
b us d.
• Th motor us s dir ct curr nt, so that th r ar no
conc rns about voltag s and fr qu nci s.
• Th motor g n rat s l ss h at than conv ntional
units.
Th spindl motor has an up-to-sp d tim of 700 ms.
1.2.4 Carriag R ad/Writ Ass mbly H ads
Th r ad/writ h ads touch ach sid of th fl xibl disk,
allowing data to b writt n to th fl xibl disk and to b
r ad from it. Th r ad/writ h ads ar part of a pr cision
carriag ass mbly that shifts th h ads from track to track.
During th loading of a fl xibl disk, th r ad/writ h ads
ar h ld away from th surfac of th fl xibl disk.
1.2.5 St pping Motor
Th st pping motor, und r microproc ssor
th carriag ass mbly with a t nsion d
arrang m nt provid s fast and accurat
ach puls th st pping motor r c iv s,
shaft rotat s 1.8 d gr s. This action,
carriag 1/2 track on th fl xibl disk.
control, positions
st l b lt. This
data acc ss. For
th st pping motor
in turn, mov s th
1.2.6 H ad Load Cam Ass mbly
Th h ad load cam ass mbly (rotary sol noid) low rs th
h ads onto th fl xibl disk with a forc that is controll d
by a microproc ssor. This action pr v nts damag to th
fl xibl disk and r duc s w ar of th r ad/writ h ads.
1-3

1.2.7 Pop-Up F atur
For asy r moval of th fl xibl disk from th disk driv ,
th pop-up f atur j cts th fl xibl disk from th disk
driv wh n th door is op n d. Aft r j ction, th dg of
th fl xibl disk protrud s approximat ly 1/2 inch (13 mm)
from th disk driv .
1.2.8 Ind x S nsor
Th ind x s nsor is a combination LED and phototransistor
that s ns s th ind x position of th fl xibl disk. Th
Mod l FD1165 has a dual ind x s nsor to d t ct both singl 
sid d and dual-sid d fl xibl disks.
1.2.9 00 Track S nsor
Th 00 Track s nsor d t cts wh n th r ad/writ h ad is at
th 00 track (track 0, sid 0).
1.2.10 Writ Prot ct S nsor
Th writ prot ct s nsor d t cts th pr s nc or abs nc of
a writ prot ct notch on th fl xibl disk. If th r is a
notch, th writ function is disabl d. If no notch xists,
th writ function op ration is nabl d.
1.2.11 M dia-In S nsor
Th m dia-in s nsor d t cts th pr s nc of a fl xibl disk
in th disk driv .
1.2.12 Coll t Ass mbly
Th coll t ass mbly holds th fl xibl disk in position on
th spindl wh n th door is clos d.
1.2.13 Print d Circuit Board (PCB)
Th PCB (not shown) supports th l ctronic driv and logic
circuits of th disk driv .
1.2.14 Variabl Fr qu ncy Oscillator (Optional)
Th optional Variabl Fr qu ncy Oscillator (VFO) PCB mak s
th int rfac signals to th controll r mor stabl , in
cr asing th ov rall r liability of th disk driv .
1-4

1.2.15 Display Lamps
Two lamps on th front pan l provid a visual display of th
r ady and busy stat s of th disk driv .
1.2.16 Front Pan l
Th front pan l holds th display lamps and provid s an
attractiv app aranc for th front of th disk driv .
1.2.17 Movabl Door Handl
Th movabl door handl , wh n clos d, ngag s th coll t
ass mbly.
1.2.18 Door Lock Sol noid
Th door lock sol noid (not shown) mak s it impossibl to
r mov th fl xibl disk during c rtain driv op rations,
th r by pr v nting data loss or physical damag to th
fl xibl disk.
1.3 SPECIFICATIONS
Tabl 1-1 lists th sp cifications for th Mod l FD1165
Fl xibl Disk Driv .
Tabl 1-1 FD1165 Sp cifications
1-5

Tabl 1-1 FD1165 Sp cifications (cont'd)
1-6