NCR Decision Mate V - Page 27

Figure 2 .9 I/O signals (1 o f 5)
Pin Pin I/O
D es c riptio n D C Characteristics
N am e N um be r
D riv er o r Receiver Re 
qu irem en ts o f each
Peripheral
+ 5
a1
_
+ 5 V Sup p ly
c1
—
I m ax . = 0 .5 A
+12
c2
-
+ 1 2 V Su p p ly
I m a x. = 0.1 A
LG R D
c1 6
_
a 3 2
—
Logic ground
c32
BDO c6
I/O
Data-B us lines (8 -b it) b id irec tio n a l, active high D river: l|_ > 2 m A
BD 1
a6
I/O
or I l > 1 .6 m A
B D 2 c7
I/O
Bus-Driver to periph eral B U S (L S 2 4 5 ) ,
a u to m atic d ire c tio n .
by V l < 0 .4 5 V
B D 3
a7
I/O
l|-|> -0 .2 m A
B D 4 c8
I/O
S w itc h by IF S E L (I/O -R e a d ). N orm a l o u tp u t.
Receiver: l[_ < - 0 .2 m A
B D 5 a8 I/O
l(-l< 2 0 p A
B D 6 c9
I/O
D ire ction can be changed by D IR / signal.
B D 7 a 9
I/O
Ty p ica l IC's in the interfaces are 74 L S 2 4 5 or
Po rt 8 2 5 5 .
S Y S T E M T E C H N IC A L M A N U A L H A R D W A R E D E S C R I P T I O N
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