The DX-7 synthesizer completely reset the synthesizer market when was released in 1983. There is a legendary story which sound programmer Dave Bristow was given the brief to create 128 preset sounds within a week for the first release.
In this interview for Cult-Sounds.com, Dave recalls the story - essentially they thought they were doing 32 (the initial design brief from Yamaha), and had spent months create them for the launch. But when they arrived in Japan were told "actually we've decided on 128, and we need them by Monday"
The rest is history as the DX-7 went on to be one of the best selling synthesizers of its time - we think maybe the MicroKorg has pipped it now.