Saw this video on Create Digital Music:
Intro to The Drumssette by Mike Walters.
The Drumssette was built by Mike Walters in 2010.
The Drumssette is a Tascam four track cassette recorder that I
turned into a programmable drum machine. A cassette with four
tracks of repeating drum sounds can be mapped into a 16 step
rhythm using the 64 switches on the interface. The audio on the
cassette tape also clocks the sequencer.
More details at www.mysterycircuits.com