Analog function generator ICs?
This would seem to be similar to the XR2206 :)


  The XR2209 is a monolithic voltage-controlled oscillator (VCO) integrated circuit featuring excellent frequency stability and a wide tuning range. The circuit provides simultaneous triangle and squarewave outputs over a frequency range of 0.01Hz to 1MHz. It is ideally suited for FM, FSK and sweep or tone generation, as well as for phase-locked loop applications.
  
  Applications
  
  
  Waveform Generation Triangle, Sawtooth, Pulse, Squarewave