> -----Original Message----- > From: cctalk [mailto:[email protected]] On Behalf Of Fred Cisin > via cctalk > Sent: 01 January 2018 20:36 > To: General Discussion: On-Topic and Off-Topic Posts <[email protected]> > Subject: RE: ZX Spectrum Z80 Keeps Resetting > > Is there a random element to the rebooting, or is it a fixed specific pattern? > > Consider, . . . > if some high order bits of the address are non-functional, then when it goes to > location xxx000 , it starts over at 000000. > > Not necessarily the most likely cause of the problem.
Unfortunately it is random. To a point. When I did my trace with the logic analyser I could see it was in a RAM testing loop and would fail part way through the loop, failing on an address that previously worked. However, it manages to get past that bit and gets to the point where the copyright message is displayed. But it always resets at that point. I have not been able to capture that point in the address trace to see if it is a consistent address, but maybe that is something I can try with a trace that triggers on a stop condition. I will try that this evening. Regards Rob
