Tandy 1400LT - Internal Keyboard Check

@ Internal Keyboard Check
Q
Check if keyboard
connector
is loose.
I
Check the keyboard
Select Signal
Pin17
of GATE4.
(Low : Internal)
I
NO
1
I Check GATE4 1
I 1
Replace the
keyboard unit.
YES
1
I Keyboard unit I
I failure.
I I
Keyboard control
failure.
Check the
key switch.
ICheck the
key matrix.1
C80 and C81
I
Check the keyboard data
I GATE4 - Pin6-13
I
Check GATE4
5-1 1