Atari ST series Technical Reference Manual page 209

Format Floppy Disk Track
Flopfmt()
F l o p f m t ( ) f o r m a t s a n d v e r if ie s a s i n g l e t r a c k o f a f l o p p y d i s k . T o f o r m a t
a n d in itia liz e a d i s k , y o u m u s t c r e a t e a b o o t s e c t o r a n d c l e a r t h e f ir s t t w o
tr a c k s , in a d d i t i o n t o f o r m a t t i n g a ll t h e t r a c k s .
C macro format
l o n g b u f f e r , s k e w t a b l , m a g i c ;
i n t s t a t u s , d e v n u m , s p t , t r a c k n u m ,
s i d e n u m , i n t r l e v , m a g i c , in itia l;
s t a t u s = F l o p f m t ( b u f f e r , s k e w t a b l , d e v n u m , s p t ,
t r a c k n u m , s i d e n u m , i n t r l e v , m a g i c , in itia l)
Machine language format
m o v e . w
m o v e .l
m o v e . w
m o v e . w
m o v e .w
m o v e . w
m o v e .w
m o v e .l
b u f f e r , - (s p )
m o v e .l
m o v e . w
t r a p
a d d .l
Inputs
in itia l
m a g i c
i n tr le v
s i d e n u m
t r a c k n u m
s p t
d e v n u m
# i n i t i a l , - ( s p )
# m a g i c , - (s p )
# i n t r l e v , - (s p )
# s i d e n u m , - (s p )
# t r a c k -
n u m , - ( s p )
# s p t , - ( s p )
# d e v n u m , - ( s p )
s k e w t a b l , - (s p )
# 1 0 , - ( s p )
# 1 4
# 2 6 , s p
w o r d
l o n g
w o r d
w o r d
w o r d
w o r d
w o r d
Flopfmt
A 1 6 -b it v a l u e to w h i c h a ll o f t h e d a t a
b y t e s in a s e c t o r a r e in itia lly s e t (u s u a l l y
$ E 5 E 5 ) .
M u s t b e s e t to $ 8 7 6 5 4 3 2 1 .
S e c t o r i n t e r l e a v e f la g 1 =
- 1 = s k e w e d .
S i d e o f t h e d i s k t o f o r m a t ( 0 o r 1 ).
T r a c k n u m b e r t o b e f o r m a t t e d ( n o r m a l l y
0 - 7 9 ) .
S e c t o r s p e r t r a c k . N o r m a l l y s e t to 9 .
T h e d r i v e n u m b e r ( 0 =
1 = d r i v e B :) .
Opcode = 10
n o r m a l ,
d r i v e A :,
201