Motor controller

I am installing a new motor control for my Sherline 2000 and need to
know whether the 90V DC motor uses a full or half wave field voltage.
Also, I am assuming that this motor is a shunt wound DC since it has
5 wires (2 for armature, 2 for field and 1 ground), is this correct?
My new control will allow for the speed to be controlled through a
PWM signal. Any cheap pwm generators (~10V) out there which can be
controlled easily through one pin on the parallel port?