image courtesy of Benjamin Ward

The 100m is totally unlike the System 100, both in appearance and sound. The sound of the 100m is said to be "thinner" and more precise than the 100. The 100m is more truly modular, with a series of different modules which are bolted into a rack (see picture below of a patched System 100m courtesy of Benjamin Ward) . The rack supplies the necessary 8-pin DIN power connectors for the modules as well as an internal CV/gate and trigger system (thereby making the System 100m a "semi-modular" due to the fact that, for simple patches, patch chords are not needed). The racks came in different sizes. The 190 was a smaller, three-module, rack with a few connection sockets at the base. The 190B was a base unit that would elevate the 190 above a keyboard. The 191 and 191J are five-module racks, the 191J having a set of multiple connectors on its base. Available modules include:

• the M-110 VCO, VCF, and VCA
• the M-112 dual VCO, with 3 CV ins, two outs, and weak/strong sync
• the M-121 dual VCF, with an added high-pass filter
• the M-130 dual VCA, with a linear/exponential switch
• the M-131 Mixer, 4 X 2 X 1, with panning and a tuning oscillator (220/440/880Hz)
• the M-132 dual Mixer and Voltage Processor
• the M-140 dual Envelope (ADSR, invertable, and manual gate button) and LFO (five waveforms with switchable range: x1, x1/10)
• the M-141 dual Envelope, Gate Delay, and Invert/Adder
• the M-150 Ring Mod, Noise (pink and white), S&H (with lag), and LFO (five waveforms with switchable range: x1, x1/10)
• the M-160 Computer Interface
• the M-165 Double Portamento Controller, with CV in
• the M-170 Pitch/Voltage Converter, Envelope Follower, and Audio Amp
• the M-172 Phase Shifter, Audio Delay, LFO, Gate Delay
• the M-173 Quadruple Signal Gate and six 4-way Multiples
• the M-174 Parametric Equalizer, four-band, with 20Hz to 20kHz center frequencies
• the M-180 Keyboard, 32-note (F-C) low note priority, with transpose switch and portamento knob
• the M-181 Keyboard, 49-note (C-C) same as M-180 but with added portamento switch and bender lever (with CV out)
• the M-182 Analog Sequencer, 2 X 8 step, serial or parallel
• the M-184 Keyboard, 49-note (C-C) 4-voice, with switchable mono/polyphonic, an arpeggiator, and polyphonic portamento

[from The A-Z of Analogue Synthesizers, by Peter Forrest, published by Susurreal Publishing, Devon, England, copyright 1994 Peter Forrest]