Atari ST series Technical Reference Manual page 213

Get I/O Buffer Record
Iorec()
I o r e c ( ) r e t u r n s t h e a d d r e s s o f a d a t a s t r u c t u r e k n o w n a s t h e I /O b u f f e r r e ­
c o r d , c o n t a i n s i n f o r m a t i o n a b o u t t h e i n p u t b u f f e r u s e d b y a s p e c if ie d d e ­
v i c e .
C macro format
i n t d e v ;
l o n g b u f r e c ;
b u f r e c = I o r e c ( d e v ) ;
Machine language format
m o v e . w # d e v , - ( s p )
m o v e . w # 1 4 , - ( s p )
t r a p # 1 4
a d d q .l # 4 , s p
Inputs
d e v w o r d
Results
DO b u f r e c l o n g
T h is r e c o r d c o n t a i n s 1 4 b y t e s o f d a t a , in t h e f o r m a t .
T h e c o n t e n t s o f t h e d e v i c e 's b u f f e r r e c o r d p o i n t e d to b y
Byte Number Element Name
0 - 3 ib u f
4 - 5 ib u f s iz e
6 - 7 ib u f h d
8 - 9 ib u f tl
1 0 - 1 1 ib u f lo w
1 2 - 1 3 ib u f h i
F o r t h e R S - 2 3 2 d e v i c e o n l y , a n o u t p u t b u f f e r r e c o r d f o llo w s i m m e d i a t e l y
a f t e r t h e i n p u t b u f f e r r e c o r d .
Iorec
T h e i n p u t d e v i c e w h o s e b u f f e r r e c o r d y o u
w i s h to f in d :
0 = R S - 2 3 2 s e r ia l p o r t
1 = C o n s o l e k e y b o a r d
2 = M I D I p o r t
T h e a d d r e s s o f th e d e v i c e 's b u f f e r r e c o r d .
Contents
A d d r e s s o f th e i n p u t b u f f e r
S iz e o f t h e i n p u t b u f f e r (in b y te s )
I n d e x to h e a d ( n e x t w r i t e p o s i tio n )
I n d e x to ta il ( n e x t r e a d p o s i tio n )
Low water
m a r k
High water
Opcode = 14
bufrec:
m a r k
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