"Garland Gray II" wrote in
news:Zchxf.6624$CV.5318@dukeread03:

Uh Larry, how can I determine whether it is negative ground?
I've looked around on it and the battery. I tried to test the battery
contacts w/ my multimeter, but the probes were too fat, and I wasn't
sure I'd be more than guessing which was the ground contact anyway.
I called Toshiba support, and he couldn't answer that kind of
question.


Obviously, you're going to use your own 12V power cord after you figure
out which contacts on the plug are + and which are minus, right?
So....take the battery out so we don't blow the ohmmeter in your
multimeter with its DC, then measure from the + power wire to the shell
(ground) on the serial DB9 connector. If they are connected together,
it's positive ground. Try the same for the - power wire to audio and
serial ground.

I'm concerned about someone's comment their starting of the big diesel
blew a directly-connected notebook like this. Maybe all this is not a
good idea, after all.

Perhaps the $29 75-watt DC-to-AC inverter from any Radio Shack, which is
so efficient there's no fan and it's all built right into the plastic
plug, would be a better idea to plug your laptop's AC supply into. The
smaller the inverter, like this tiny one, the less its wasted idle
current drain. I doubt you could measure this little guy's DC unloaded
current without a milliammeter. Its LED indicator is probably its
largest idle load. Your notebook hardly draws 75 watts to charge the
battery and power the computer. If it won't, graduate to the 150W
version.