A rare operational Apple-1 computer inscribed with the inventory number #22 is being offered on eBay with no reserve, providing someone the chance to own a piece of personal computing history.

The machine was owned by one-time Apple Computer employee and Atari programmer Joey Copson.

It is distinguished from other Apple-1s by a "futuristic custom plastic case that ... Copson placed it in", according to the auction listing.

Apple-1s often had a custom finish because they were "sold as a fully-assembled circuit board, but minus a case, power supply, keyboard or monitor".

According to a registry of Apple-1 computers, it is not the first time the Copson Apple-1 has been offered for sale, but at least this time it is much more likely to sell.

The registry notes the Copson machine – with a starting bid of US$170,000 (A$223,684) – failed to sell on eBay in December 2011.

Auction house Christies also tried to move it a year later. Expectations were a more reasonable US$126,000, with a US$80,000 reserve, but bidding reached only a shade over US$50,000.

One reason it is expected to sell this time around is it actually works. Less than 10 of the known 63 units still confirmed to exist can actually boot up.

When Copson's Apple-1 was auctioned last in 2012, it was described as "inoperable" in press reports.

Sometime after it was passed in by Christie's, it was acquired by Bob Luther, who crowdfunded and wrote a book on the first Apple machines.

He enlisted Corey Cohen, another Apple-1 expert, to service and "fire up" the Copson machine in September 2014.

Cohen put it through its paces by running Microsoft BASIC "and also an original Apple-1 Star Trek game".

He cleaned and performed "minor repairs" on the Apple-1 motherboard, and refurbished some of the add-on components.