featured 12-bit sampling with a frequency range up to 40 kHz and up to 750 kB of memory that allowed for just under 12 seconds at the best sampling rate. It could store a maximum of 32 samples in memory. The operating system was software based and allowed for upgrades that had to be booted each time the sampler was switched on. The Akai MPC60 Digital Sampler/Drum Machine and MIDI Sequencer (1988) was the first non-rack mounted model released. It is also the first time a sampler with touch sensitive trigger pads was produced by AKAI, giving birth to the popular MPC series of sampler sequencers. The Akai S950 (1988) was an improved version of the S900, with a maximum sample frequency of 48 kHz and some of the editing features of the contemporary S1000. The Akai S1000 (1988) was possibly the most popular 16-bit 44.1 kHz stereo sampler of its time. It featured 16-voices, up to 32 MB of memory, and 24-bit internal processing, including a digital filter (18 dB/octave), an LFO, and two ADSR envelope generators (for amplitude and filtering). The S1000 also offered up to 8 different loop points. Additional functions included Autolooping, Crossfade Looping, Loop in Release (which cycles through the loop as the sound decays), Loop Until Release (which cycles through the loop until the note begins its decay), Reverse and Time Stretch (version 1.3 and higher). Other samplers released by AKAI include the S01, S20, S700, S2000, S2800, S3000, S3000XL, S3200, S5000, S6000, MPC500, MPC1000, MPC2000, MPC2000XL, MPC2500, MPC3000, MPC3000XL, MPC3000LE, MPC4000, MPC5000, Z4 and Z8. Roland Roland Corporation manufactured the S series. These were true samplers that provide all of the features described above, including sampling, sample editing, pitch transposition, and keyzone mapping: Roland S-10 Roland S-50 Roland S-330 Roland S-550 Roland S-760 Roland S-770 More recently, Roland introduced the Groove Sampler concept. These devices are renowned for their ease of use, but a few lack the pitch transposition and keyzone mapping capabilities that most samplers have. Some have limits to rendering loops or sound effects samples that are played back at the same pitch they were recorded. Although these machines are equipped with a wide range of built-in effects, a few lack pitch transposition and keyzone mapping that diminishes their utility significantly. The Roland Groove Sampler line includes the following: Roland DJ-70MKII Roland DJ-70 Roland JS-30 Roland MC-909 Roland MC-808 Roland MC-09