23 Jan
2008
23 Jan
'08
3:38 a.m.
On Tuesday 22 January 2008 22:10, Richard Beaudry wrote:
6) One thing that seems odd is that the ADxx
(Address/Data) lines seem
"stuck". The scope does not show a waveform, and measuring with a meter
shows some lines right at +5VDC, some at about +4VDC and some at 0VDC.
Perhaps the processor is indeed HALTed???
The exact value measured probably isn't important, but if the scope isn't
showing any activity then it may be caused by the various buffers and such
not being enabled by whatever it is that controls them (it's been a *long*
time since I looked at the schematic for one of those :-). These are
probably slightly different values because they're different chips, maybe.
Figuring out what's supposed to be controlling those might be a next step.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin