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T h e unit is m o d i f i e d f o r R a d i a l S e l e c t o p e r a t i o n b y ch a n g in g j u m p e r s b e t w e e n the
e x i s t i n g e t c h pads.
Hard S e c t o r
In the b a s i c c o n f i g u r a t i o n , the u s e of a hard s e c t o r d i s k c a u s e s the INDE X l i n e to
p r o d u c e o n e ind ex p u l s e and 32 s e c t o r p u l s e s p er e a c h d i s k re v o l u ti o n .
With the Hard S e c t o r op tio n i n s t a l l e d , the ind ex and s e c t o r p u l s e s a r e s e p a r a t e d
and s u p p l i e d to the c o n t r o l l e r on in d epe nd ent IND EX and S E C T O R l i n e s .
1 6 / 8 S e c t o r
Whe n the Hard S e c t o r o p t io n is i n s t a l l e d , the a d d it io n o f the 1 6 / 8 S e c t o r option
p r o v i d e s a 2 - b i t b i n a r y c o u n t e r that cou nt s down the 32 s e c t o r p u l s e s f r o m a h ar d -
s e c t o r d is k .
T h i s co un td ow n p e r m i t s e a c h t r a c k to be d iv id ed into 16 o r 8 s e c t o r s ,
i n s t e a d o f 32 s e c t o r s .
s t a g e (8 s e c t o r s ) is c o n n e c t e d to the S E C T O R output li n e to the c o n t r o l l e r .
Auto E r a s e
T he e r a s e t u r n - o n and t u r n - o f f d e l a y s a r e i n t e r n a l l y c o n t r o l l e d b y the E r a s e lo g i c .
When the c o n t r o l l e r a c t i v a t e s W R I T E , the l e a d i n g ed ge of WRITE i n i t i a t e s a
2 0 0 - m i c r o s e c o n d e r a s e t u r n - o n de lay ; the t r a i l i n g ed ge of WRITE i n i t i a t e s a
5 3 0 - m i c r o s e c o n d e r a s e t u r n - o f f d el a y.
a s t r a d d l e - e r a s e head m u s t b e in s t a l l e d .
P a d s a r e p r o v i d e d f o r i n s t a l l a t i o n of this option.
Dat a S e p a r a t o r (FM only)
In the b a s i c c o n f i g u r a t i o n , the RAW DATA l i n e to the c o n t r o l l e r p r o d u c e s a p u l s e
f o r e a c h flux r e v e r s a l r e a d f r o m the dis k .
c o n t a i n s both c l o c k and data p u l s e s .
c i r c u i t s that s e p a r a t e the c l o c k and data p u l s e s .
T h e Dat a S e p a r a t o r op tio n is i n s t a l l e d f o r the d i s k d r i v e to o p e r a t e in the s i n g l e
d e n s i t y e n c o d i n g m o d e (FM) on ly.
and c l o c k p u l s e s input o v e r the RAW DATA li n e .
T h e e t c h pads a r e l o c a t e d on the m a i n print ed c i r c u i t boa rd.
Th e output of the f i r s t s t a g e (16 s e c t o r s ) , o r the s e c o n d
F o r t h is r e a s o n , the c o n t r o l l e r m u s t have
When i n s t a l l e d , this o p tio n s e p a r a t e s the data
If the s t r a d d l e - e r a s e c o n f i g u r a t i o n is u s e d ,
T h is o p t io n r e m o v e s the t i m e d e l a y s .
C o n s e q u e n t l y , the RAW DATA input
Data p u l s e s a r e s u p p li ed to the
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