C i r cu i t Descr i pt i on ( cont ' d )
C l ock
T h e c l ock c i r cu i t ' s ma i n compon e n t
( 1 6 MHz OS
C
. ) p r oduces a
s i gna l
when vo l t age
I s a p p l i ed .
T h i s
s i gna
I
I s a p p I I e d t o U 37 .
a dua I D
t ype f l i p- f l op .
T h e f i r s t
1 / 2
f l i p- f l op d i v i de s t he s i gna l b y 1 / 2
( 8 MHz ) wh i ch goes d i r e c t l y t o t he
m i c r o p r ocessor
( U 1 p i n 1 5 ) .
T h e
same 8 MHz s i gna
I
I s a p p I I e d t o U 47
p i n 1 0
wh i ch
supp l i e s t he c l ock for
t he wa t c h dog c i r cu i t . U 37
p i n 9
sends a 4 M H z s i gna l t o U36 p i n
2
for t he S a f e RAM k e y c l ock .
CLOCK C I RCU I T D I AGRAM
$ l P B
1 0 K
F i g . 3-8
4 l,fHI
3 .
MPU
BOARD
NOT E S
7 4 HC74
3-25
Summary of Contents for 5000 Plus
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Page 125: ...3 MPU BOARD Troub l eshoot i ng cont d CLOCK D I AGRAM Vee 3 68...
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Page 242: ...HOPPER CONTROL BOARD Boar d Assemb l y AS 3556 1 3 o 0 o Q5 r 7 4...
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Page 361: ...1 5 APPEND I CES APPEND I X 4 Co i n Mechan i sm I nc 1 5 6...
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Page 383: ...APPEND I X 6 Ser v i ce Su i l e t i ns 1 5 APP END I CES 1 5 1 2...
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