Stepper Motors

I've been lurking - and learning - for several weeks now and the time has
come to join in. Having been slowly drawing up a specification for the
conversion of a Taiwan mill/drill to CNC, I finally decided to order a 5A
3-axis driver from Camtronics. This was on 11-11-01, the day after Dan
Mauch announced that he had sold out!

I had, perforce, to design my own, not too difficult after a lifetime in the
electronics industry before changing course completely (see
http://www.shaymaker.pwp.blueyonder.co.uk .)

There are some aspects of stepper motors, however, which puzzle me a little.

The motors I am using are specified as follows:-

Current rating per phase

Motor #1 Motor #2

Unipolar 4.3A 3A
Bipolar series 3A 2.1A
Bipolar parallel 6A 3.5A

Am I right in thinking that these are maximum currents before magnetic
saturation occurs? The figures for Motor #2 don't seem to make a lot of
sense compared with Motor #1.

When setting up the driver, with the stepper stationary and the relevant
winding drawing current, which value do I use in each instance?

I'm sure there are simple answers, but I seem to be going round in circles
getting nowhere.

I'd appreciate any help you can give.

Many thanks,

Mike Chaney