It gradually became feasible to include high quality samples of existing instruments as opposed to synthesizing them. In 1988, Korg introduced the last of the hugely popular trio of digital synthesizers of the 1980s after the DX7 and D50, the M1. This heralded both the increasing popularisation of digital sample-based synthesis, and the rise of 'workstation' synthesizers. After this time, many popular modern digital synthesizers have been described as not being full synthesizers in the most precise sense, as they play back samples stored in their memory. However, they still include options to shape the sounds through use of envelopes, LFOs, filters and effects such as reverb. The Yamaha Motif and Roland Fantom series of keyboards are typical examples of this type, described as 'ROMplers'; at the same time, they are also examples of "workstation" synthesizers.