This Module is currently available.
CGS92 Smooth & Stepped Generator
This module is a variation on the Classic Serge Smooth and Stepped Generator module built by Lower West Side Studio. The SSG can be used as an oscillator as well as a complex voltage generator.
From the 1982 Serge catalog:
The SMOOTH & STEPPED FUNCTION GENERATOR (SSG) is s a complex multi-functional module to provide various slew and sample functions.
The Smooth section will place a positive and negative slew (glide) on a changing input voltage for lag effects, voltage controlled portamento, and non-linear, low frequency filtering. With the CYCLE jack patched to the input, the Unit will oscillate yielding a voltage controlled triangle wave LFO. A high level into the HOLD input will hold the current output level, whether the unit is oscillating or processing an external control voltage. This is identical to a track-and-hold function.
The Stepped function can be used as a sample-and-hold with voltage controlled slew rate limiting. Slew rate limiting limits the size of the step at the output. With the step size limited to a small value, if the input is a random voltage, the output is a random voltage also, but it will only vary slightly from step to step, gradually covering the entire range of the input random voltage. No large changes in the output will be allowed. With the Cycle jack patched to the input and a trigger applied to the Sample input, complex staircase waveforms are generated.
The COUPLER is an internal comparator comparing the Smooth and the Stepped outputs. This is useful for generating complex control voltages and for patching a random voltage generator.
The Lower West Side Studio version of the CGS92 features Loop switches on both the Smooth and Stepped sections allowing the signal to be routed from the Cycle Out jacks back to the Inputs without the need for additional cables.
https://richsstudioproject.wpcomstaging.com/product/cgs92-smooth-stepped-generator/
These merchants probably sell this module. Huh?