Service manual
MZ-80K
• Audio/Clock Block
07
-\
DO
--I
RO
WR
CS
A1
AO
Programmable
counter
(8253)
--
WR
--
CS
--
RO
~
31.25KHz
'1
--
J
Clock
function
INT
1/2
frequency
J>
Au
division
2MHz
I
Latch
Oscillator
circuit
for
Tempo
I
DO
Block Diagram
of
Parts
around
Audio/Clock
Block
Problem
Check
1.
No sound
is
produced.
Is
output
signal present at pin
@
of
IC18?
Yes; IC12, IC3
No;
IC18
2.
Sound
is
distorted.
Check
for
IC12 and IC18.
3.
Tempo
is
abnormal.
Check
for
IC13.
4. Clock fu
nction
is
abnormal.
Check
for
IC18.
-8-
dio
output