Tandy 1000 SL Technical Reference Manual page 420

(6) Confirm t h a t t h e gap between t h e upper arm and t h e am l i f t e r i s l a r g e r
than 0.2m. Refer t o Fig.3405.
( 7 ) Execute
2F w r i t e
o p e r a t i o n
(WRITE
D A T A frequency o f 250KHz f o r FD-55BR
/FR and 500KHz f o r FD-55GR) f o r one r o t a t i o n o f t h e d i s k .
( 8 ) Unload t h e head.
( 9 ) Repeat t h e head loading and unloading a l t e r n a t e l y ( t a p p i n g o p e r a t i o n )
and observe t h e waveform of TP7
o r TP8
by t h e o s c i l l o s c o p e .
(10) S e t t h e o s c i l l o s c o p e t r i g g e r t o t h e p o s i t i v e mode and observe t h e r e a d
waveform a t TP7 o r TP8 a f t e r t h e i n p u t o f an unload comnand.
(11) Confirm t h a t t h e r e i s no unload l e v e l (excludes very small one) a t
lOOmsec a f t e r t h e unload command a s shown by d o t t e d l i n e i n Fig.3407.
Note: T h i s i t e m s h a l l be executed when t h e s i d e 1 head is s e l e c t e d .
I f t h e s i d e 1 head i s l i f t e d t o o high d u r i n g unload o p e r a t i o n ,
t a p p i n g sound i n c r e a s e s and d i s k wear w i l l be a c c e l e r a t e d , while
unload l e v e l w i l l be observed when it i s t o o low.
(12) S e t t h e o s c i l l o s c o p e t r i g g e r t o t h e n e g a t i v e (-1 mode and observe t h e
waveform a t Tp7 o r
Tp8 a f t e r t h e i n p u t o f a head l o a d command.
Confirm t h a t t h e read waveform
more
t h a n 50msec a f t e r t h e head l o a d
comnand i s almost s e t t l e d .
O r
confirm t h a t bottom
"A"
of t h e r e a d l e v e l more than 35msec a f t e r t h e
i n p u t o f t h e head l o a d command i s
more
t h a n 0.7 a g a i n s t t h e average
read l e v e l "B".
(A/B
2
0.7 i n Fig.3407)
(13) Make t h e head move t o t h e innermost t r a c k .
(14) Repeat t h e procedure from i t e m ( 7 ) t o ( 1 2 ) .
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3408
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