Tandy 6000 HD, Service Manual

Page: 278 / 416

DISK CHANGE
T h is s tra p p a b le f e a tu r e p ro v id e s a t r u e (lo w )
s ig n a l to th e in t e r f a c e w h e n D r iv e S e le c t is a c ­
t iv a t e d i f th e d r iv e h a s g o n e fr o m a R e a d y to a
N o t R e a d y c o n d itio n w h ile d e se le cte d . T h is
lin e is re s e t o n th e tr u e - to - fa ls e t r a n s it io n o f
D r iv e S e le c t i f th e d r iv e h a s gone to a R e a d y
c o n d itio n .
TWO-SIDED
T h is o p tio n is a v a ila b le o n ly o n M o d e l
T M 8 4 8 -2 E . T r u e (lo w ) in d ic a te s t h a t a tw o -
s id e d d is k e tte is in s ta lle d .
F ig u r e 3-1 c o n ta in s th e e le c t r ic a l in te r fa c e
c h a r a c te r is tic s . F ig u r e 3-2 c o n ta in s th e c o n tr o l
a n d d a ta t im i n g re q u ir e m e n ts .
3.5
d
.
c.
POWER
D . C. p o w e r is s u p p lie d to th e d r iv e t h r o u g h a
s ix - p in A M P c o n n e c to r, J 2 , m o u n te d o n th e
c ir c u i t b o a rd . T h e m a t in g c o n n e c to r, n o t
s u p p lie d , is A M P P a r t N u m b e r 1 -4 8 0 2 7 0 -0 ,
u s in g A M P c o n ta c t P a r t N u m b e r 6 0 6 1 9 1 -1 .
P in a s s ig n m e n ts a re fo u n d in T a b le 3-2.
T h e c h a ssis s h o u ld be c o n n e c te d to e a r th
g r o u n d to e n s u re p ro p e r o p e ra tio n .
TYPICAL INTERFACE
CHARACTERISTICS
L in e s b e tw e e n th e c o n t r o lle r a n d th e d r iv e
h a v e th e f o llo w in g c h a r a c te r is tic s :
V . T r u e = + 0 .4 v o lt m a x im u m a t I ,
out out
= 4 8 m illia m p e r e s , m a x im u m
V out F a ls e = + 2 .4 v o lts m in im u m open
c o lle c to r a t I , = 250
out
m ic ro a m p e re s , m a x im u m
TABLE 3-2
D. C. POWER CONNECTOR
PIN ASSIGNMENTS
P in S u p p ly V o lta g e
1
+ 2 4 v o lt s D . C.
2
2 4 v o lt s R e tu r n
3
5 v o lt s R e tu r n
5
+ 5 v o lt s D . C.
6
R e tu r n
FIGURE 3-1
ELECTRICAL INTERFACE CHARACTERISTICS
3-6