This may sound like a simple-minded question, but this is the first time
I've ever had a need for this:

I've been designing some relatively simple chip circuits based on things
like photoresistors (you know, no light to photoresistor, emit a logic
high, etc.).

Anyway, I've got some servos lying around, and I wanted to do some things
with them using digital logic.  I know all about having to pulse the signal
and everything, I just have one problem:  I'm assuming I need a negative
(yes, negative) logic high to get the thing to turn in the direction 
opposite the direction it would turn under normal logic high.

Is a negative logic high (I've seen this in schematics) the same thing as
an active low, or what?  I'm not using a bi-polar power source, so how
would I get a negative logic high out of this thing?  I need to have all
three signals available:  Logic high, logic low, and negative logic high.

Any help would be greatly appreciated.  Also, please reply via email, as I
never seem to have time to read this (or any other) group lately.

Thanks much,
-mark