Bally 5000 Plus, Manual

Page: 349 / 388

1 4 .
GLOSSARY
v
ve i n--T h e p l as t i c e x t ens i ons f r om t he code r i ng t h a t b l o ck ( i n t e r r up t ) t h e
em i t t e r f r om t he de t e c t o r i n t he U-shaped o p t i c sensor s .
Vcc--T h e 5 . 0 VDC used on t he p r i n t e d c i r cu i t boa r d s .
VMA--va l i d memo r y a d d r e s s . S i gna l s e n t t o a 6800 c h i p ( de v i ce ) i nd i c a t i ng a
va l i d a d d r e s s on t h e a d d r e s s bus a n d t h e m i c r oprocessor i s sync h r on i z e d t o
enab l e . VMA on l y r e s ponds t o a VPA i nput s how i ng t he dev i ce i s a 6800 .
VPA--v a l i d per i p h e r a l add r e s s . S i g na l i nd i ca t i ng t he c h i p ( de v i ce ) i s o r i s t o
be u s e d a s a 6800 dev i ce . T h e da t a t r a n s f e r s h ou l d be s yn c h r on i ze d
w i t h
t he e n a b l e ( E ) s i gna l . T h i s i nput i n d i ca t e s t h a t t he m i c r op r ocessor s hou l d
use a u t oma t i c vec t o r i ng f o r an i n t e r r u p t .
w
wa l t
s
t a t e--R a t e a t w h i c h 68000 r ece i ve s DTACK .
wor d--A
g r oup o f 1 6 b i t s ope r a t e d on a s a un i t .
WR I TE--S l gna l d e f i n i ng t he d a t a bus t r an s f e r a s a r e ad o r w r i t e cyc l e on t h e
I / O
boa r d .
1 4-6