The only surviving Apple-1 personal computer that was actually sold out of Steve Jobs’  garage in Los Altos, California, is scheduled to go up for auction Dec. 11. Jobs sold the now seemingly ancient piece of technology for $600 in 1976. Christie’s auction house expects it to fetch between $400,000 and $600,000 once it goes up for sale.

Known as the Ricketts Apple-1 personal computer, named after original buyer Charles Ricketts, the computer is the only surviving model that’s known to have been sold directly by Apple founder Jobs, according to a Christie’s press release. It’s being sold by Robert Luther, a Virginia-based collector who bought the computer by accident when he purchased the contents of a police storage locker without knowing what was inside.

“It all started with the Apple-1, and with this particular machine," Andrew McVinish, the auctioneer’s director of decorative arts, told the Guardian. “When you see a child playing with an iPad or iPhone, not too many people know that it all started with the Apple-1. So to be able to own a machine that started the digital revolution is a very powerful attraction.”

Of the hundreds of Apple-1 computers that were produced, less than 50 are known to still survive. The machine in question was purchased in 1999 by an entrepreneur named Bruce Waldack, though he was forced to sell the item after losing his fortune in 2004.

The provenance has been established by a series of cancelled checks written in Ricketts’ hand noting that the computer was “purchased in July 1976 from Steve Jobs in his parents’ garage in Los Altos.” That check will be sold along with the Ricketts computer.