Rapture oscillators

I'm not sure exactly what you mean by dsp based.  It can load both samples and single cycle wavetables.  Due to the wave Rapture Pro's engine handles the wavetables, they can be transposed across the entire keyboard without aliasing.  There are a bunch of basic single cycle waveforms included such as multiple sawtooths, square waves, sines, etc.  There's also the waveguide oscillator mode.  Here you load an impulse and it is processed through a waveguide.  This originated in Dimension Pro, but the waveguide parameters weren't changeable.  I don't think you can play with the waveguide parameters in Rapture Pro either, but I'm not sure about that.
Dan

There are two kinds of wavetables - the kind in Rapture and those that waldorf and Ensoniq used to make.  They are tables of wave shapes, basically different samples that are stapled together to form one long wave -  64 waves is common.  You can use an envelope or lfo etc. to cycle through the "wave," producing rhythmic and radically changing oscillators shapes. 

lfm
What you might miss from standard synths is PulseWidthModulated square.

There's a workaround to get a PWM pulse wave in Rapture.  You need to use a sawtooth wave and a ramp (inverted saw) with a phase offset.  The two waves add together to give you a pulse.  The phase offset determines the width.  Rene, Rapture and Dimension Pro's original designer, posted a tutorial on this forum back when Rapture first came out.  
http://forum.cakewalk.com/Secrets-of-Rapture-PWM-m788580.aspx
 
Unfortunately the links to the .wav files you need are broken so you would have to create them yourself.
Dan