Kenwood DP-1100 B Service Manual page 122

D P - 1 1 0 0 B II
W h e n A T is m o r e t h a n 5 1 2 t r a c k s , c o n s i d e r i n g the effect of
disc e c c e n t r i c i t y a n d brake o p e r a t i o n , A T + 2 ( 1 2 8 t r a c k s are
a d d e d ; refer t o T a b l e 3 - 1 D ) is c a l c u l a t e d a n d a kick o p e r a t i o n
in w h i c h the p i c k u p is c a r r i e d by m o r e t h a n the c a l c u l a t i o n
value is p e r f o r m e d . On the o t h e r h a n d , w h e n A T is less t h a n
5 1 2 t r a c k s a n d if the a b o v e s a m e m e t h o d is p e r f o r m e d , the
d i f f e r e n c e b e t w e e n the required n u m b e r of tracks a n d the
n u m b e r of t r a c k s by w h i c h the p i c k u p is actually carried is
v e r y large. T o c o m p e n s a t e t h i s , the o p e r a t i o n s h o w n in Fig.
3 - 1 G is m a d e , i.e., kick o p e r a t i o n by w h i c h the p i c k u p is car­
ried by 3 1 t r a c k s is e x e c u t e d in intervals of 3 msec r e p e a t e d ­
ly. T h e u p p e r limit in the n u m b e r of repetitions d e p e n d s o n the
p e r f o r m a n c e of external c i r c u i t . Since the p e r f o r m a n c e of ex­
ternal c i r c u i t m a y be greatly c h a n g e d hereafter, the m a x i m u m
n u m b e r of repetitions is c o n t r o l l e d by v a r y i n g the inputs t o
p o r t pins K M A X a n d KMAXn (only i m m e d i a t e l y after p o w e r
0
O N ) . T h e f o l l o w i n g table s h o w s the relationship b e t w e e n t h e
m a x i m u m n u m b e r of repetitions a n d these i n p u t s .
KMAXj
K M A X
0
0 1
1 0
1 1
T h e d y n a m i c s e a r c h s y s t e m , based o n TOC d a t a , c a n be ex­
e c u t e d o n l y w h e n T N O alone is d e s i g n a t e d as the s e a r c h i n g
p r o g r a m N o . ( X = 0 1 is d e s i g n a t e d ) . T h e r e f o r e , w h e n X is also
d e s i g n a t e d , d y n a m i c search o p e r a t i o n w h i c h is a little dif­
f e r e n t f r o m t h e system based on TOC data is e x e c u t e d . T h e
d i f f e r e n c e is t h a t after the s e a r c h i n g p r o g r a m N o . a n d the pre­
s e n t p r o g r a m N o . c o i n c i d e , kick search o p e r a t i o n takes p l a c e .
For e x a m p l e , w h e n T N O = 3 a n d X = 8 are d e s i g n a t e d for the
s e a r c h i n g p r o g r a m , d y n a m i c search o p e r a t i o n to T N O = 3 is
p e r f o r m e d a n d the p i c k u p is m o v e d at high speed t o w i t h i n
t h e t h i r d p r o g r a m area, after w h i c h kick search o p e r a t i o n is
e x e c u t e d .
In a d d i t i o n , w h e n TOC data is n o t read o u t , d y n a m i c search
o p e r a t i o n c a n n o t be p e r f o r m e d . In this c a s e , t h e r e f o r e , all
s e a r c h o p e r a t i o n is p e r f o r m e d in the kick search s y s t e m .
A g a i n s t this c a s e , in D P - 1 1 0 0 B / I I , a self-learning f u n c t i o n of
TOC data is p r o d u c e d by w r i t i n g in external R A M the absolute
t i m e o n c o m p l e t i o n of search o p e r a t i o n so t h a t the subse­
q u e n t s e a r c h o p e r a t i o n c a n be p e r f o r m e d p r o m p t l y .
3. OPERATION OF MAIN MICROPROCESSOR
Maximum repetitions
4
8
6
T a b l e 3 - 1 C
Next, the kick s e a r c h s y s t e m is d e s c r i b e d .
In this s y s t e m , search o p e r a t i o n is p e r f o r m e d based o n only
the address data read o u t .
Here, the amount of pickup m o v e m e n t is c o n v e r t e d to the
number of t r a c k s w h i c h is represented by s t a g e No. Nor­
mally, at first, operation begins w i t h the greatest a m o u n t ,
then the amount is lowered according to the searching pro­
gram and the pickup is m o v e d in the b a c k w a r d direction.
T h i s p r o c e s s is performed repeatedly. T h u s , the amount of
pickup m o v e m e n t is controlled s o that the kick operation is
necessarily completed before the searching program.
In D P - 1 1 0 0 B / I I , 9 stages for a m o u n t of p i c k u p m o v e m e n t
are set as s h o w n o n Table 3 - 1 D .
Stage
1
2
3
4
5
6
7
8
9
Table 3 - 1 D Relationship b e t w e e n s t a g e s and s e t numbers
of t r a c k s
In the table, c o n c e r n i n g p l a y t i m e conversion value, the value at
the left in the parenthesis represents the t i m e required to m o v e
the n u m b e r of tracks at the o u t e r - m o s t side of disc and the
value at the right is for the inner-most side. For the operation,
the c o d e (2 < K I C K > t o D < K I C K > ) c o r r e s p o n d i n g t o each
stage is o u t p u t to s e m i - c u s t o m
T C 1 5 G 0 0 0 8 A P ) . Stages 7 to 9 are executed by repeatedly
performing a kick operation w h i c h m o v e s the pickup 31 tracks
and t w i c e the 1 track kick.
For e x a m p l e , stage 7 ( 6 4 tracks) is executed by performing
t w i c e a kick operation w h i c h m o v e s the pickup 31 tracks and
t w i c e the 1 track kick.
Fig. 3 - 1 F
Set number of tracks (pickup movement
time conversion value (sec))
1 track ( 0 . 3 3 - 0 . 1 2 )
3 tracks (1 - 0 . 4 )
5 tracks ( 1 . 7 - 0 . 6 )
7 tracks ( 2 . 3 - 1 )
15 tracks ( 5 - 2 )
31 tracks ( 1 1 - 4 )
64 tracks ( 2 1 - 8 )
128 tracks ( 4 3 - 1 6 )
256 tracks ( 8 5 - 3 2 )
IC15 ( T 7 0 0 0 1 — 0 0 0 7 or