A fully operational Apple I computer with documentation showing that it was purchased direct from Steve Jobs is being auctioned by Christies on 11th December. It is the only surviving Apple I known to have been personally sold by Jobs in 1976. Originally bought for $600, the auction house says it is expected to sell for more than half a million dollars, reports Reuters.

The so-called Ricketts Apple-1 Personal Computer, named after its original owner Charles Ricketts and being sold on Dec. 11, is the only known surviving Apple-1 documented as having been sold directly by Jobs, then just 21, to an individual from the Los Altos, California family home, Christie’s said.

Ricketts died with the computer in storage. The current owner, Robert Luther, bought it in 2004 from a police auction.

“I knew it had been sold from the garage of Steve Jobs in July of 1976, because I had the buyer’s canceled check,” Luther wrote on a kickstarter page soliciting funding for a book on the machine’s history. “My computer had been purchased directly from Jobs, and based on the buyers address on the check, he lived four miles from Jobs.”

In an interesting twist, the cancelled check formed part of the evidence used to achieve historical listing status for the Jobs family home in Los Altos, just over a year ago.

The auction estimate of $500-600K may prove an under-estimate: fewer than 50 Apple I computers survive, and another fully-working model without the Jobs documentation sold last month for $905k.

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