In the 1980s, Roland sold a number of synths with minimal controls for patch programming or editing, with the expectation that many performers would not often build or edit patches themselves -- they would either stick to the factory patches, or buy patch files from third-party sound designers. For performers who did want to build their own patches, Roland made available a programmer, a separate device with a control for each patch parameter, which connected to the synth via MIDI except for the PG-200 and 800. Here is a list of Roland programmers: