You reported that pin 26 is low, look at the power on reset circuit.
The Z80 only needs a short low pulse to reset itself.
It must he high for the Z80 to run.
MZ-80K displaying garbage chars on screen
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- Posts: 18
- Joined: Tue Apr 17, 2018 8:38 am
- Location: Germany, Hamburg
Re: MZ-80K displaying garbage chars on screen
fetch all RAM ics and clean the contacts ... i just had this issue with some dust on the chips. And i had to replace my system EPROM ... a fresh burnt one runs fine.
Have an eye on the tantal caps inside the powers supply and dont forget to check the cap in the power SWITCH
Have an eye on the tantal caps inside the powers supply and dont forget to check the cap in the power SWITCH
Collecting -K- since 1978
Supporter of Karl Heinz Maus famous MZ site ;)
Supporter of Karl Heinz Maus famous MZ site ;)