VT101 8085 CPU Fault
bobalan at sbcglobal.net
Sun Jan 18 14:11:07 CST 2015
On 1/18/2015 12:07 PM, Robert Jarratt wrote:
> No, I checked that and it isn't. It is an active low signal and it is high.
What about the READY pin? Stuck low?
>> -----Original Message-----
>> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of tony
>> Sent: 18 January 2015 19:16
>> To: General Discussion: On-Topic and Off-Topic Posts
>> Subject: RE: VT101 8085 CPU Fault
>>> 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?
Dentopedalogy is the science of opening your mouth and putting your foot in it.
I've been practising it for years.
More information about the cctalk