Christie's is hoping to beat the auction record for an Apple-1 computer on December 11 in New York, with the news coming just one month after the top price so far was achieved at Bonhams.
The computer is the first produced by the company formed by Steve Jobs and Steve Wozniak back in 1976. Prices have been rising steadily since Jobs' death in 2011, with almost every auction bringing a new record sum.
However, there were just 50 of the computers ever made, and just a scant few of those remain in working order.
The working example sold at Bonhams was sought after as a rare version that had seen no modifications or upgrades, leaving it in highly original condition. It made $905,000, raising the previous record by 35.4%.
The computer will now go on display at the Henry Ford Museum, Michigan.
The Apple-1 at Christie's is known as the "Ricketts" example, after its first owner, Charles Ricketts, who bought it directly from Steve Jobs. Jobs had built the computer in his parents' garage.
Having passed to DigitalNation entrepreneur Bruce Waldack in the late 1990s, the computer was then sold at a sheriff's sale of Waldack's property in 2004. Here, it was acquired by renowned Apple collector Bob Luther.
Fully operational, the Apple-1 has been started by expert Corey Cohen who ran the original software programme Microsoft BASIC as well as the Star Trek game that was released with the machine. It is being sold with two cancelled cheques, one of which is labelled "Software NA Programmed by Steve Jobs".
It was previously believed that Jobs had not undertaken much of the programming for the computers, but evidence such as this cheque has revealed that Jobs was integral to the process and soldered many of the circuits, as well as making adjustments for his close customers.
Also selling will be the Ron Wayne Apple Archive at $30,000-50,000, which includes working proofs of the original Apple-1 Operation Manual. The manual will be hot property on sale day, displaying the oldest copy of an Apple logo in existence.
Ron Wayne was co-founder of Apple Computer but left the partnership 11 days later, retaining a consultant role for some years.
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