Bally 5000 Plus, Manual

Page: 79 / 388

3 . MPU BOARD
C i rcu i t Descr i pt i on ( cont ' d )
Reset
T h e reset c i r cu i t s i gna l s t he
m i c roprocessor t o beg i n p rocess i ng
f rom a k nown s t a t e ( f r e s h s t a r t ) .
T h e r es e t c i r cu i t I s
wh i c h d i sp l ay s " R E S ET "
Message Cen t e r b y t he
cond i t i on s .
co l d s t a r t ( powe r up )
a c t i va t ed
on t he
fo l l ow i ng
wa rm r ese t ( R E S E T but t on-SW1 )
s t a t i c de t e c t
wa t c h dog
R E S E T C I RCU I T D I AGRAM
U l
R E S E T
S I P S
Vee
U 2 1
10K
74HC05
U21 "-"
5
410 �
R I 2 LEO I
74HC 1 0
l
1 8 R E S E T
Vee
S I P S
1 0 K
8
17
Vee
S I P I
10K
Vee
S l P 8
1 0 K
I U 2 1
5 5 5
U 3 9
WoO
74HC05
1 M
Vee
C R I
NOT E S
Vee
R 2
1 �
R E S E T
A N T.
C 2
p e T R A e E
Mi'd
R 3
I K
I . . . .
8
M i d
.
F i g .
3-6
3-22