Spectravideo MKI, Service – Technical Manual

Page: 131 / 134

( 3 )
E l e c t r i c a l Cha r ac t e r i s t i c s
( 1 ) S igna l
l e v e l s
A l l input / o u t p u t s i gna l s a r e
TTL
l eve l .
"HIGH"
l e ve l
" LOW'"
l e v e l
+ 2 . 4
-
s . ov
+0 . 0
-
0 . 4V a t t
h
e P r i nt e r inp u t t
e
r
m i
na
l
s
-
-
Tf
'
I
I
T --: �
Tr
( 2 )
Inpu t /Ou t pu t
c ond i t i ons
Tf and Tr
=
1 00 ns or l e s s
T va l ue shown on
t
h
e
t iming
cha r t
Inpu t / o u t p u t s
i
g
n
a l
s
a r e pu l l e d u p w i t h 1 0 k ohms .
*
Input
s i g na l s
The
input
load cor re spond s to one 74LS04
*
O u t p u t
s i gna l s
The
ou t p ut c o r r e s ponds
to a 7 4LS04 . The recommended ou tput
l oa d corre sp ond s t o
one
LSTTL l oa d .
'
'
+S ( V]
t oo n '.. t ok n
Input
llOOOpF,_'
t._
These are attached
74LS04
equivalent
to the INITIAL and
signals.
+S ( V)
I Ok il
Output
74LS04
equivalent
4 . 98