A working Apple-1, the first home computer ever released by Apple, is valued at $300,000-500,000 ahead of a sale at Bonhams San Francisco on October 22.
The lot is a hugely important piece of recent history, being one of the first 50 made by company co-founder Steve Wozniak in 1976.
Christina Geiger, director of Bonhams' books and manuscripts department in New York, commented: "It is a great privilege to be selling this Apple-1 at auction.
"It has exceptional provenance and condition. Moreover, it will be the first Apple-1 to be publicly exhibited for auction in the Bay Area.
"It is very gratifying to think of this computer returning to within 40 miles of its birthplace."
The founder of a Cincinnati-based computer club acquired the computer in 1980. He recognised its importance early on and kept it in a display cabinet.
It was tested in August by Apple-1 expert Corey Cohen, who commented: "This is one of the best examples of a working early Apple-1 board that I have seen.
"The condition is unlike the other Apple-1 computers that have come up for sale before. This one has had no modifications ever performed or removed; even the screws on the power regulators aren't heat cycled."
The record for an Apple-1 stands at $667,960 for an example signed by Wozniak. It sold at Auction Team Brekker in Cologne, Germany last year.
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