Spectravideo SVI 318 Service – Technical Manual page 88

8 2 5 5 P o r t A ( I nput P o r t )
DO P ad d l e o r Tab l e t Inpu t
P a dd l e o r Tab l e t Input
D 1
D 2 P a d d l e o r Tab l e t I nput
P a dd l e o r Tab l e t I npu t
D3
T r i gg e r Sw i tch ( B u t t on ) o f J oy s t ick 1
D4
D 5 T r i gg e r Sw i t c h ( B u t t o n ) o f Jo y s t i ck 2
C a s s e t t e R e a dy ( 0
D6
D 7 Ca s s e t t e R e a d D a t a
8 2 5 5 P o r t B ( I nput P o r t )
DO - D7 ----- Keyboard R e a d D a t a
8 2 55 P o r t C ( O u t put P o r t )
DO - D3
D4
D 5
D6
D7
8 2 5 5 Con t ro l Word ( W r i te On l y )
In i t i a l S e t
R e a dy , 1
=
Keybo a r d BCD O u t p u t Da t a ( Fo r Keyboa r d S cann i ng )
Ca s s e t te M o t o r On ( 0
Ca s s e t t e Wr i t e Data
Ca s s e t t e Aud i o Cont r o l ( 1
M i x P S G S o und Da ta
D 7
D 6 D 5
1 0 0
4 . 55
J
0
J
1
not r e a dy )
==
M o t or On , 1
== ==
E nab l e other channe l
==
( 0
D i s ab l e o t h e r channe l i n )
==
D4 D3 D 2 D 1
1 0 0
1
P r e s se d
==
No Conne c t
==
Mo t o r O f f )
i n ;
DO
0