Tandy 6000 HD, Service Manual

Page: 264 / 416

DAISY CHAIN CAPABILITY
DISKETTE LEVER LOCK SOLENOID
(OPTIONAL)
T h e d r iv e p ro v id e s t h e a d d re s s s e le c tio n a n d
g a t in g f u n c tio n s n e c e s s a ry to d a is y c h a in a
m a x im u m o f f o u r u n it s a t th e u s e r’s o p tio n .
T h e la s t d r iv e o n th e d a is y c h a in te r m in a te s
th e in te r fa c e . T h e t e r m in a t io n s a re a c c o m ­
p lis h e d b y a r e s is to r a r r a y p lu g g e d i n t o a D IP
s o c k e t.
INTERNAL TRIM ERASE
T h e d r iv e p ro v id e s th e c o n tr o l s ig n a ls neces­
s a ry f o r p ro p e r t r i m e ra s u re o f d a ta .
INDUSTRY STANDARD INTERFACE
COMPATIBILITY
T h e d r iv e is c o m p a tib le w i t h c o n tr o lle r s t h a t
use a n in d u s t r y s ta n d a r d in te r fa c e .
ACTIVITY INDICATOR
A n a c t i v i t y in d ic a to r , lo c a te d on th e f r o n t
p a n e l, is a u t o m a t ic a lly illu m in a t e d w h e n th e
d r iv e is s e le c te d . T h is f r o n t p a n e l L .E .D . is
a ls o used as a n in d ic a t o r i n th e d ia g n o s tic
m ode.
DIRECT DRIVE, BRUSHLESS D. C.
MOTOR
T h e s p in d le m o to r is a c r y s ta l c o n tro lle d ,
d i r e c t d r iv e , b r u s h le s s D . C. m o to r f o r
im p r o v e d m o t o r s t a r t t im e , a n d sp e e d
a c c u ra c y .
COMPACT SIZE
T h e re d u c e d size o f th e d r iv e o ccu p ie s o n ly
o n e - h a lf th e m o u n tin g space r e q u ir e d f o r a
c o n v e n tio n a l d r iv e .
T h e d is k e tte le v e r lo c k s o le n o id is c o n tr o lle d
b y th e h o s t s y s te m .
1.4 FUNCTIONAL DESCRIPTION
T h e d r iv e s a re f u l l y s e lf-c o n ta in e d , a n d
r e q u ir e n o o p e r a t o r in t e r v e n t io n d u r in g
n o r m a l o p e ra tio n . E a c h d r iv e c o n s is ts o f a
d ir e c t d r iv e , s p in d le s y s te m , a h e a d p o s itio n in g
s y s te m , a n d a r e a d / w r it e s y s te m .
T h e T M 8 4 8 -1 E is a s in g le -s id e d d r iv e . T h e
T M 8 4 8 -2 E is a d o u b le -s id e d d r iv e . T h e o n ly
d iffe r e n c e b e tw e e n th e tw o d r iv e s is th e
n u m b e r o f he a d s. T h e c ir c u i t b o a rd is id e n t ic a l
f o r b o th m o d e ls .
W h e n th e d is k e tte le v e r is opened, access is
p ro v id e d f o r th e in s e r tio n o f a d is k e tte . T h e
d is k e t t e ’s ja c k e t is a c c u r a te ly p o s itio n e d b y
p la s tic g u id e r a ils . I t s lo c a tio n is e n s u re d b y
th e b a c k s to p a n d d is k e je c to r.
C lo s in g t h e d is k e tte le v e r a c tiv a te s th e
c o n e /c la m p s y s te m , r e s u lt in g i n a c c u ra te
c e n te r in g a n d c la m p in g o f th e d is k e tte to th e
d r iv e h u b . T h e d r iv e h u b is d r iv e n a t a c o n ­
s t a n t speed o f 36 0 R P M b y a c r y s ta l-
c o n tro lle d , d ir e c t d r iv e , b ru s h le s s D . C. m o to r.
T h e h e a d is lo a d e d in t o c o n ta c t w i t h th e
r e c o r d in g m e d iu m w h e n e v e r th e d is k e tte
le v e r is la tc h e d .
T h e h e a d s a re p o s itio n e d o v e r th e d e s ire d
t r a c k b y m e a n s o f a s te p p e r m o to r /b a n d
a s s e m b ly a n d it s a s s o c ia te d e le c tro n ic s . T h is
p o s itio n e r uses a 3.6 d e g re e r o t a t io n t o ca u s e a
one t r a c k lin e a r m o v e m e n t.
W h e n a w r ite - p r o te c te d d is k e tte is in s e r te d
in t o th e d r iv e , th e W r it e P r o te c t s e n s o r d is ­
a b le s th e w r it e e le c tro n ic s o f th e d r iv e , a n d a
W r it e P r o te c t s ta tu s o u t p u t s ig n a l is a v a ila b le
to th e in te r fa c e . W h e n p e r fo r m in g a w r it e
o p e ra tio n , a 0 .0 1 3 -in c h w id e , n o m in a l, d a ta
t r a c k is re c o rd e d . T h e n , t h is t r a c k is t u n n e l
e ra s e d to 0 .0 1 2 -in c h , n o m in a l.