A rare, fully operational Apple I computer, nicknamed the "Hatfield" model, is heading to auction this fall. Originally sold for $666.66 in 1976, the same unit fetched $671,400 in 2013. Bonhams estimates the October 14 auction will see it sell between $500,000 and $800,000.

This particular machine is nicknames for its original owner, Fred Hatfield, and is listed at No. 48 on the Apple I Registry. There are reportedly fewer than 75 surviving Apple I computers today, and even fewer that remain functional. The motherboard is signed by Apple co-founder Steve Wozniak.

Accompanying the computer is a 1978 letter signed by Steve Jobs, detailing a trade-in offer for the early machine. Auction Team Breker Köln / YouTube The computer will be displayed in Los Angeles from September 9 to 11, Boston from September 21 to 23, San Francisco from September 30 to October 1, and New York during the October sale. Only around 200 Apple I computers were produced, making this a significant piece of tech history.

The sale highlights the evolution from hobbyist hardware to modern computing empire.