Robert Henke has released MicroDrum, a free drum machine instrument for Max for Live.
MicroDrum is a rough emulation of an old school 8 bit drum sample cell with some ideas borrowed from Roger Linn.
Samples can be truncated at the beginning, facilitated by the zoom (Zoom) function which displays only 10ms of the drum sample, starting from the start point. Samples can be tuned up and down two octaves (Tune). Tuning can be quantized to semitones using the step function (S). There is a volume envelope for shortening the decay (Decay), and an anti aliasing filter (HiCut).
What makes the specific sound of 8 bit drum computers is the low sample rate, which can be emulated with the (Down) parameter, a value of 2 means at 44.1kHz that the sample rate of the non-detuned drum sample equals 22.05kHz. The higher the (Down) parameter, the lower the sample rate and the more gritty and low-fi the sound will become.
The other important factor is bit resolution. With 8 bit there are only 256 steps for the amplitude value at a given moment. With 16 bit there are 65536 steps!
The device is a free download at Robert’s website.