Tandy 1000 SL Technical Reference Manual page 138

28 DRATE 16ma 54 0 Data r a t e
s e l e c t
LOW,
500 kbps
is
s e l e c t e d . When
is
H I G H
250kbps
i s
s e l e c t e d .
( O . C . )
s i g n a l . When
i s
29
30
3 1
32
3 3
34
35
36
37
38
FDCRST 4ma 46
RESET 66
MTRONB 16ma 53
( O . C . )
FDHSELI 4 2
FDHSELOB 16ma 49
(O.C.)
FDWREI 4 1
FDWREOB 16ma 50
(O.C.)
FDD I R I 40
FDDIROB 16ma 5 1
( O . C . )
FDCCHPB 4ma 47
0
I
0
0
0
FDC
r e s e t
s i g n a l t o
t h e FDC c o n t r o l l e r
when i s
H I G H .
System r e s e t i n p u t
s i g n a l when
i s
H I G H .
Floppy d i s k motor ON
o u t p u t s i g n a l when
i s
LOW.
Head
s e l e c t
i n p u t
s i g n a l from f l o p p y
d i s k c o n t r o l l e r . .
Head
s e l e c t
i n p u t
s i g n a l f o r f l o p p y
d r i v e s when
i s
LOW.
Write
e n a b l e i n p u t
s i g n a l from f l o p p y
d i s k c o n t r o l l e r .
Write
e n a b l e o u t p u t
s i g n a l f o r f l o p p y
d r i v e s when
i s
LOW.
Head t r a v e l
d i r e c t i o n i n p u t
s i g n a l from F D C
c o n t r o l l e r .
H e
ad t r a v e l
d i r e c t i o n f o r f l o p p y
d r i v e .
FDC c h i p
s e l e c t
o u t p u t s i g n a l o r F D C
c o n t r o l l e r when
i s
LOW.
6