I . I N T R O D U C T I O N
The DS-1000 is a dual channel RS-232C asynchronous serial
c o m m u n i c a t i o n a d a p t e r f o r t h e P S / 2 . T h e D S - 1 0 0 0 i s d e s i g n e d
t o b e u s e d i n t h e S e r i a l 1 t h r o u g h S e r i a l 8 a d d r e s s r a n g e a s
s p e c i f i e d f o r t h e P S / 2 , a l t h o u g h e i g h t o t h e r a d d r e s s e s a r e
a v a i l a b l e f o r a p p l i c a t i o n s r e q u i r i n g a d d i t i o n a l s e r i a l p o r t s .
T h e a v a i l a b l e i n t e r r u p t s e l e c t i o n s ( I R Q 3 , 4 , 7 and 9 ) c a n b e
u s e d t o r e d u c e t h e n u m b e r o f i n t e r r u p t s o u r c e s o n a s i n g l e
interrupt input. This feature can reduce software overhead in
interrupt driven, high throughput applications.
T h e D S - 1 0 0 0 s e r i a l i n t e r f a c e i s a c c o m p l i s h e d t h r o u g h a
p a i r o f 1 6 5 5 0 A s y n c h r o n o u s C o m m u n i c a t i o n E l e m e n t s ( A C E s ) . T h e
1 6 5 5 0 i s c o m p a t i b l e w i t h t h e 8 2 5 0 a n d 1 6 4 5 0 A C E s u s e d i n t h e
I B M P C / X T / A T m o d e l s . T h e 1 6 5 5 0 a l s o h a s a n a d d i t i o n a l F I F O
mode that reduces CPU overhead at higher data rates.
The DS-1000 address and interrupt selections are selected
t h r o u g h t h e P r o g r a m m a b l e O p t i o n S e l e c t ( P O S ) u s i n g t h e I B M
i n s t a l l a t i o n u t i l i t i e s . I n a d d i t i o n , j u m p e r s a r e p r o v i d e d o n
t h e D S - 1 0 0 0 t o c o n f i g u r e t h e a d a p t e r a s D a t a T e r m i n a l
E q u i p m e n t ( D T E ) o r D a t a C o m m u n i c a t i o n s E q u i p m e n t ( D C E ) .
D T E / D C E s e l e c t i o n c a n e a s e t h e c a b l i n g b u r d e n i n l o c a l
applications where MODEMS are not required.
I I . B O A R D D E S C R I P T I O N
A component diagram of the DS-1000 showing the locations
o f t h e 1 6 5 5 0 A C E s , D T E / D C E c o n f i g u r a t i o n j u m p e r s , a n d D - 9
c o n n e c t o r s i s s h o w n i n F i g u r e 1 . T h e f i r s t c o m m u n i c a t i o n
channel is controlled by the 16550 labeled U27, jumper J1, and
is accessed through connector P1. The second channel uses the
1 6 5 5 0 l a b e l e d U 2 8 , j u m p e r J 2 , a n d i s a c c e s s e d t h r o u g h
connector P2.
iv
Summary of Contents for DS-1000
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