VT101 8085 CPU Fault

Johnny Billquist bqt at update.uu.se
Mon Jan 19 07:07:08 CST 2015

On 2015-01-19 09:04, tony duell wrote:
>> I just found something interesting, the pin activity on the address lines, RD, WR, ALE etc appears normal for a bit,
>> and only after a few seconds does it all become inactive.
>> Perhaps this really is an indication that the ROM is bad, if it is getting into some kind of loop where it does no
>> external activity. I don’t really know the 8085 to know whether that is possible.
> What if (due to ROM or RAM problems maybe) the 8085 executed a HLT instruction?

I didn't know it had a halt instruction, which is why I speculated 
(negatively) about that in a previous reply.
But if it do indeed have a halt, then this would be a very possible 


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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