901-A OSCILLATOR CONTROLLER:
Used to control the frequencies of two or more 901-B oscillators (see below) so that the ratio between the frequencies of the controlled oscillators remains constant.
$85.00
901-B OSCILLATOR:
Provides sine, triangular, pulse, and sawtooth waveforms simultaneously over the frequency range 0.1 - 15,000 cycles per second. Two or more of these can be ganged, and their frequencies controlled from a single 901-A controller. Complex spectra and note mixtures can be produced, and can be shifted over wide frequency ranges.
$125.00
901-C OUTPUT STAGE:
In conjunction with a 901B oscillator, this instrument produces two outputs of equal magnitude, but opposite sign, of any of the 901B waveforms. The output is variable, and is used as a control voltage.
$45.00 (Only 15 of these modules were produced)
901-D VARIABLE WAVEFORM OUTPUT STAGES:
In conjunction with a 901B oscillator, this instrument produces two outputs of equal magnitude but opposite sign. All of the 901B waveforms are available and may be mixed in any proportion. In addition, variable clipping is provided to shape the triangular wave. Outputs are used as control voltages.
$75.00 (Only 8 of these modules were produced)

From "Ultra-Short Form Catalog of Electronic Music Composition Instruments", R.A. Moog Company, October, 1965.

SCHEMATICS