Atari ST series Technical Reference Manual page 207

Read Floppy Disk Sector
Floprd()
T h is f u n c t i o n is u s e d to r e a d o n e o r m o r e s e c t o r s o f in f o r m a t i o n f r o m a
f lo p p y d is k .
C macro format
in t s t a t u s d e v n u m , s e c n u m
t r a c k n u m , s i d e n u m , n u m s e c s ;
l o n g b u f , r e s v d ;
s t a t u s = F l o p r d ( b u f , r e s v d , d e v n u m , s e c n u m ,
tr a c k n u m , s i d e n u m , n u m s e c s ) ;
language format
Machine
m o v e . w # n u m s e c s , - ( s p )
# s i d e n u m , - ( s p )
m o v e . w
# t r a c k -
m o v e .w
n u m , - ( s p )
# s e c n u m , - ( s p )
m o v e .w
m o v e .w # d e v n u m , - ( s p )
-(sp)
c lr .l
b u f , - (s p )
m o v e .l
m o v e . w # 8 , - (s p )
# 1 4
t r a p
a d d .l # 2 0 , s p
Inputs
w o r d
n u m s e c s
s i d e n u m w o r d
tr a c k n u m w o r d
s e c n u m w o r d
w o r d
d e v n u m
lo n g
r e s v d
lo n g
b u f
Results
DO s t a t u s w o r d
See also
Flopwr(), Flopver()
Floprd
T h e n u m b e r o f c o n t i g u o u s s e c t o r s to
r e a d .
T h e s id e o f t h e d i s k to r e a d f r o m (0 o r 1 ).
T h e n u m b e r o f th e d i s k tr a c k a t w h i c h to
b e g in r e a d i n g .
T h e s e c t o r n u m b e r a t w h i c h to b e g in
r e a d i n g ( s e c t o r s a r e u s u a l l y n u m b e r e d
f r o m 1 t o 9 ) .
T h e n u m b e r o f t h e d r i v e to r e a d
(0 = d r i v e A :, 1 =
A l o n g w o r d w h o s e v a l u e is i g n o r e d , b u t
w h i c h m u s t b e p r e s e n t a s a p l a c e h o l d e r .
T h e a d d r e s s o f a b u f f e r w h e r e t h e d a t a
f r o m o n e o r m o r e s e q u e n t i a l s e c t o r s m a y
b e s t o r e d .
A n e r r o r c o d e f o r t h e f u n c t i o n . A v a l u e o f 0 m e a n s
th e o p e r a t i o n w a s s u c c e s s f u l . A n y n e g a t i v e v a l u e
r e p r e s e n t s a s y s t e m e r r o r .
Opcode = 8
d r i v e B :) .
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