ranman,
The 3977 does microsteppig and the 297/298 on does full/half. You can run higher power supply voltage with 297/298 new version. 297/8 is much easier to solder. The only three axis version of either is in my basement in debug and driving me nuts because of using the small version of the 3977 and it's almost impossible to solder without special tools.
Phil
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
Vist my websites - http://pminmo.com & http://millpcbs.com