Q's for the stepper experts.

Hello group,

I have a question for those who understand the nature of the beast. My
reading has left me a bit confused and maybe some of you can set me
straight.

First the background. I have four (older but new) Astrosyn 5V 1A 70-80 oz.
in. steppers I want to drive in bipolar mode for a home built engraver (no
milling) I have not been able to find data on these older (designation)
astrosyns. They will be pushing 1/2"-10 Acme screws except for a forth axis
which will come later on if all works out. The current rating from what I
understand is usually given for the unipolar rating with the bipolar rating
being at 70% of this (got that from some compumotor data). Please correct me
if this is wrong.

Now with that said, I also see in some of this compumotor literature that
the windings of these six wire steppers can be run in series or in parallel.

Series hook-up being:
1A - Red
1B - Red/Wh
2A - Grn
2B - Grn/Wh
NC - Wh, Blk

Parallel hook-up being:
1A - Red
1B - Blk
2A - Grn
2B -Wh
NC - Red/Wh, Grn/Wh

I'm assuming to run with a bipolar chopper drive I would want to run with a
series connection. Is this a correct assumption? If so what current limit
setting should I be using using on each drive for each motor if the above is
incorrect?

My next question is has to do with the (up to) 2A drives I'm looking at.
They will take a 12VDC to 18VDC source for the motors.

What voltage/current for my power supply should I be looking at to drive all
4 of these motors with a 5V tap off of the main supply?

I want to give thanks in advance for all replies,

Donald Brock