1 Jan
2018
1 Jan
'18
12:56 p.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Adrian
Graham via cctalk
Sent: 01 January 2018 20:45
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Subject: Re: ZX Spectrum Z80 Keeps Resetting
It could be caused by bus contention, which may
also be the cause of
the resetting. Possibly some of the decode logic has failed, and is
allowing two
I?d be interested in putting my diagnostic ROM on that just to see what it
throws up. In the absence of having it in front of me so I can do that is the ROM
socketed? You can easily burn your own if so.
The ROM is not socketed. I have found that every time I desolder something from this board
I end up damaging the through holes, just the suction from my de-soldering gun was enough
to remove the "eyelet" today when removing a capacitor. I could socket it though
as that would be useful anyway, and I can check the ROM contents and make sure it reads OK
multiple times.
Regards
Rob
devices to drive the data bus at the same time.
I've seen this
before,
and it
does cause spikes on the 5V rails.
That is interesting, I hadn't considered that. Given that it gets a
fair way into the boot sequence it would have to be an intermittent failure.