A modular synthesizer marketed by Roland in the 1979-1983 time period. It was one of two modular systems made by Roland at this time, and was intended to be a less expensive alternative to Roland's high-end System 700. It is not to be confused with the similarly-named, but not modular, System 100.
System 100m modules were built in a unique format, and were all the same size. About 15 modules were offered, consisting mostly of common functions such as VCOs, VCFs, VCAs, and mixers. It was necessary to mount the modules in a case supplied by Roland; the cases, which were offered in 3- and 5-module widths, contained power supplies and an internal bus for internally conveying CV/Gate signals from the keyboard to normalled connections in certain modules (e.g., the pitch CV would be normalled to the frequency input of a VCO). These could be overriden with patch cords. Each module connected to the power supply and the CV/Gate bus via a DIN cable; these protruded from the back of the case and were subject to damage when gigging. The case contained a panel below the module mounting area which contained a front panel connection for the keyboard, mults, and interconnects between the 3.5mm phone jacks used by the modules, and 1/4" phone jacks. The power supply was mounted behind this panel.
A choice of three keyboards was offered. The most basic one, the model 180, had a span of 32 keys; it contained a switch that could transpose the keyboard up or down one octave, a vernier control that could be used for tuning, and a built-in lag processor for portamento generation. The model 181 added a pitch wheel (apparently the first version of the Roland pitch stick), whose output could either be added to the key control voltage, or output separately. The model 184 was the high-end keyboard; it has the ability to output separate CV/gate signals for up to four played notes simultaneously, and it also contained a built-in arpeggiator.
Although it was possible to order individual modules or a custom configuration from Roland, most systems were sold in pre-configured packages. Roland recommended purchasing a base package first, which would include a keyboard and modules for basic subtractive synthesis. Additional packages were oriented towards certain capabilities, such as percussion synthesis or orchestration.
It has been noted that the module selection offered by Roland was rather basic, and no third party ever offered compatible modules. Well after the system was discontinued, it emerged that Roland had designed an additional 6-7 modules which would have added significant further capabilities, such as a pitch to voltage converter and a type of computer interface. Although sales of the System 100m were rather brisk at the time, few remain in working condition today, and the ones that do have significant collection value.