Tandy 1400LT Service Manual page 121

Check t h e k e y b o a r d
s t r o b e s i g n a l
IC50 : P i n 2 1
a b o u t
-Id--
1 2 0 p s e c
Check IC50
Check IC50, GATE4 a n d
t h e
e n t i r e
p e r i p h e r a l
C i r c u i t r y
5-12