18 Jan
2015
18 Jan
'15
12:07 p.m.
No, I checked that and it isn't. It is an active low signal and it is high.
Regards
Rob
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
duell
Sent: 18 January 2015 19:16
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: VT101 8085 CPU Fault
CPU
The terminal controller board on my VT101 is not working, if it
displays anything it is random characters. I have used my scope to
check the 8085 CPU. It has power, it is outputting a valid clock, but
there is no activity on the RD,WR and ALE pins. I am guessing the 8085
is bad, but before I go replacing it I wanted to check if anyone knew
of anything else that might cause the 8085 to misbehave (ie am I seeing
symptoms
or a cause?).
What is the state of the reset input to the 8085? In other words, is the being held reset all the time?
-tony
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