Tandy 1000 SL Technical Reference Manual page 56

A d d r e s s
D e s c r i p t i o n
0 2FD L i n e S t a t u s R e g i s t e r
B i t D e s c r i p t i o n
6
7
Data Ready ( D R )
O v e r r u n E r r o r
( O R )
11111 =
Detect P a r i t y E r r o r (PE)
II
1
I1
= Detect F r a m i n g E r r o r ( F E )
B r e a k I n t e r r u p t ( B I 1
II
1
II
=
T r a n s m i t t e r H o l d i n g R e g i s t e r
11
1
11
= C h a r a c t e r T r a n s f e r r e d From H o l d i n g To S h i f t
Reg i s
t e r
I1
0
1 1
= L o a d i n g T r a n s m i t t e r H o l d i n g R e g i s t e r
T r a n s m i t t e r S h i f t
Register Empty
1 1 1 1 1
= S h i f t Register I d l e
11
0
II
=
Data
T r a n s f e r From H o l d i n g Register
Always L o g i c a l 1101'
02FE Modem S t a t u s R e g i s t e r
B i t
0
1
2
3
D e s c r i p t i o n
Delta Clear To S e n d (DCTS)
Delta Data S e t Ready (DDSR)
T r a i l i n g Edge R i n g I n d i c a t o r
on II
1
II
=
Off 1 1
0
II
=
D e l t a R e c e i v e d L i n e S i g n a l Detect ( I f
B i t 0,
1, 2 ,
o r 3 i s s e t t o a "l", m o d e m
s t a t u s i n t e r r u p t
i s
g e n e r a t e d )
= C l e a r To S e n d (CTS)
II
0
1 1
= Data S e t Ready (DSR) 11
0
I1
"0" = R i n g I n d i c a t o r ( R I )
"0" = R e c e i v e d L i n e S i g n a l Detect (RLSD)
0 2FF R e s e r v e d
0300-036F R e s e r v e d
0370-0377 F l o p p y D i s k C o n t r o l l e r 2 ( o p t i o n a l )
4 5