The Roland System 100m. It had three different rack sizes, the M-190 holds three modules, the M-191 and M-191J hold five. And most of their modules are multifunctional. For example; the M-110 module has a single VCO oscillator, VCF, and VCA section. So, you could cram a lot into three rack spaces. If one could get that M-190 cabinet and the 180 keyboard controller (with it's modest 2 1/2 octaves) you've got a nice, sensible set up. The dream.