Bally 5000 Plus, Manual

Page: 93 / 388

3 . MPU
BOARD
r
r cu l t D e sc r l n t i a n can t ' d )
Wr i t e d a t a wo r ds
U 3 1 and U 1 00 ope r a t e a s a pa i r . To
wr i t e
to t he d a t a wo r ds over t he
d a t a l i ne s ( 00-0 1 5 ) , t h i s pa i r
needs ( 1 ) even a d d r esses ( 2 ) c h i p
se l ec t s i gna l s ( 3 ) s a f e RAM open
and
( 4 ) t he WEL and WEH s i gna l s
s i mu l t a neous l y .
Powe r down
On powe r down , U 3 1 p i n 26 a n d U 1 00
p i n 26 r ece i ve t he l og i c LOW SAF ECE
s i gna l .
U 3 1 and U 1 00 a r e
dese l ec t e d . No I n f o r ma t i on can be
wr i t t en t o S a f e RAM .
3-36
NOT E S