Bally 5000 Plus, Manual

Page: 310 / 388

1 2 . VACUUM FLUOR ESCENT D I SPLAY BOARD
I nt roduc t i on
T h i s s e c t i on cov e r s t he v acuum f l uor e s c e n t d i sp l a y ( VF D ) boa r d . T h e p a r t s and
ob j e c t i ve s o f t h i s s e c t i on a r e a s fo l l ows :
PARTS
T h e o r y of Ope r a t i on
Boa r d Assemb l y
C i r cu i t D e s c r i p t i on
T r oub l e s hoo t i ng
Boa r d Schema t i c
OB J ECT I VE S
Know how t he va cuum f l uo r e s ce n t d i sp l a y a n d boa r d
f un c t i ons
Loca t e t he componen t s w i t h p a r t numb e r s
Know how t he va r i ous c i r cu i t s wo r k
Know how t o t r oub l e s hoot t he boa r d
Downs i ze d VFD boa r d s c h ema t i c
B i F ET--b i -po l a r f i e l d e f f e c t t r a ns i s t o r t e c h no l ogy ( B i MOS ) W i t h l og i c l e ve l s 5V
on I nput , t he h i g h vo l t age out pu t c a n be con t r o l l e d .
B i MOS--b l -po l a r me t a l o x i de sem i conduc t o r ( B i F E T ) W i t h l og i c l eve l s 5V on
i nput , t he h i gh vo l t age out pu t c a n b e con t r o l l e d .
c h a r a c t e r --One dot ma t r i x un i t con t a i n i ng 36 anode do t s o f wh i c h 35 a r e used .
T he r e a r e 40 un i t s ( c h a r a c t e r s ) w i t h 20 on e a c h r ow o f t h e d i sp l a y .
cursor pos l t l on--T h e i nd i v i dua l c h a r a c t e r s e l e c t e d t o r ece i ve t he comm a n d / d a t a .
commands-- Con t r o l s i gn a l s r ecog n i z e d by t he m i c r ocompu t e r t h a t m a n i pu l a t e t he
d a t a t o appe a r on t he Message Cen t e r .
P r eQue s t l on s
R e a d t he fo l l ow i ng Ques t i on s and w r i t e down any o t h e r Ques t i on s .
1 .
Wh a t I s t he r e f r e s h / s e l e c t c i r cu i t ?
2 . Wh a t I s a v acuum f l uo r e s ce n t d i sp l a y ?
3 . W h y does t h i s boa r d h a v e a n on-boa r d m i c r o compu t e r ?
1 2-2