VT101 8085 CPU Fault
robert.jarratt at ntlworld.com
Sun Jan 18 14:37:06 CST 2015
No stuck, high.
> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Bob
> Sent: 18 January 2015 20:11
> To: General at classiccmp.org; Discussion at classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: VT101 8085 CPU Fault
> 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
> > Regards
> > Rob
> What about the READY pin? Stuck low?
> >> -----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
> >>> 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
> > CPU
> >> being held reset all the time?
> >> -tony
> >> =
> Dentopedalogy is the science of opening your mouth and putting your foot
> I've been practising it for years.
> -Prince Philip
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