Spectravideo MKI, Сервисное – Техническое руководство, Страница: 83 / 134

The Soun d Gene r a t o r
The P S G AY-3-8 1 90 gene ra t e s a l l re qu i re d sound under sof tware con t ro l . The r e
a re t w o 8-b i t I / 0 p o r t s wh i ch a re p rogramme d a s fo l l ow :
Po r t A
Prog rammed a s input po r t and i s us e d for the inp u t s i gna l from two
j oy s t icks con t ro l l e rs .
Po r t B Programmed a s ou t p u t po r t wh ich i s us e d to ou t p u t the bank con t r o l
signa l s f o r t he memory ch i ps .
De t a i l s i g na l s f or t h e p o r t s a re l i s t e d in the t ab l e be l ow :
AY-3-8 1 90 I / 0 Port A
DO
D 1
D 2
D3
D4
D S
D 6
D 7
J oy s t ick
-
-
-
-
-
----
-
--
--
-
do
do
do
J oy s t ick
-
- -
- - do
-
- -
- do
-
-
-- -
do
1
2
AY-3-8 9 1 0 I / 0 Port B
DO Bank 1 ( Game
D 1
Bank 2 1
D 2
B ank 2 2
D3
Bank 3 1
D4
B ank 3 2
Por t )
1 No Con t a c t
0
=
Forward
0
=
Backwa r d
0
=
Le f t
0
=
R ight
0 Forward
0
=
Backwar d
0
=
Le f t
0
=
R i ght
Port )
Ca r t r idge )
D 5
Cap Lamp ( Keyboard Cap Lock)
D6
ROM 2 enab l e
1
=
D i s ab l e ; 0
=
Enab l e
D 7
ROM 3 enab l e
1
=
D i s ab l e ; 0
=
Enab l e
4 . 50
0
1
)
)
=
BANK ON
=
BANK OFF