Wozniak will work on the firm's range of solid state memory devices, which includes a PCI Nand memory system. He will also be advising the board, of which he has been a member since October 2008, on corporate strategy.
"With the revolutionary technological advances being made by Fusion-io, the company is in the right place at the right time, and ready to direct the history of technology into the 21st century and beyond," said Wozniak.
"The technology marketplace has not seen such capacity for innovation and radical transformation since the mainframe computer was replaced by the home computer.
"Fusion-io's technology is extremely useful to many different applications, and almost all of the world's servers."
The company believes that solid state drives are the way forward, in that they allow servers to manage active data. It sees disk drives as being too slow for anything other than storing processed data.
Wozniak is still technically employed by Apple and receives a small paycheck from the company every month. He is unlikely to move to Fusion-io's headquarters in Utah and will probably stay in California.
"Steve Wozniak has been among the most elite innovators of his age and we are honoured by his enthusiasm for our technology and our company," said Don Basile, chief executive of Fusion-io.
"Steve's inventions and insights have inspired generations of IT professionals, and we look forward to the influence he will have on the future direction of Fusion-io as we continue to transform the enterprise."
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