I purchased some Lin Engineering 4218L-01-10 for use with the Pololu A4983 stepper controller board and after much frustration, myself and a few other IRC Channel purveyors discovered the color coding from the Lin Engineering FAQ is incorrect, at least for this particular model. The correct color coding is... Red = B2 Blue = A2 Green = A1 Black = B1 Hope this helps alleviate some unnecessary trby Andronicus - Stepper Motors, Servo Motors, DC Motors