Early commercial digital synthesizers used simple hard-wired digital circuitry to implement techniques such as additive synthesis and FM synthesis. Other techniques, such as wavetable synthesis and physical modeling, only became possible with the advent of high-speed microprocessor and digital signal processing technology. Two other early commercial digital synthesizers were the Fairlight CMI, introduced in 1979, and the New England Digital Synclavier II, introduced in 1979 as an upgrade to the original Synclavier. The Fairlight CMI was the world's first sampling synthesizer, while the Synclavier originally used FM synthesis technology licensed from Yamaha, before adding the world's first 16-bit, real-time hard drive streaming sampler later in 1982. The Fairlight CMI and the Synclavier were both expensive systems, retailing for more than $20,000 in the early 1980s. The cost of digital synthesizers began falling rapidly in the early 1980s. E-mu Systems introduced the Emulator sampling synthesizer in 1982 at a retail price of $7,900. Although not as flexible or powerful as either the Fairlight CMI or the Synclavier, its lower cost and portability made it popular.