The Atari CDAR-504 (Also known as the "Optofile") was launched in late 1985.  Atari were the first company to utilise the Digital Research CD-ROM drivers commercially (via GEM), and believed that CD-ROM applications had a bright future in the computer market.

Although this has turned out to be true, unfortunately it wasn't the time for CD technology when Atari designed the CDAR-504.  Software was thin on the ground, and many pundits couldn't figure out how you would fill a 650MB CD-ROM with anything that would be useful to them.  Applications being designed ranged from the Boeing 747 parts guide, to various encyclopaedia products, but the cost of CD technology was far too expensive for the consumer market in 1985.  Initially, the unit had a price tag of $799, this soon came down to a more reasonable $499 in 1989.

Atari "launched" the CDAR-504 many times, but it never filtered through to the retail channel in large numbers, and any units in use were mostly sold to developers.  Again in 1988 and in 1989, Atari spoke of the infamous CDAR-504, but hardly anybody got to utilise the device.  You could call Atari direct and purchase the unit from its Sunnyvale HQ, and some dealers got a few, but it still ranks as one of those "rare" Atari products that was mostly written about and photographed at shows.

The unit offered audio left/right out, ASCI in/out and a remote control which could detach from the main housing.  It was based on a single speed Chinon drive mechanism.

In 1990 Atari officially canned the CDAR-504, there were stories of "thousands" of the units sitting in warehouses as far away as Australia! (where did they all go?).  But in true Atari style, the CD-ROM came back, and in 1991 the new CDAR-505 SCSI unit was launched and shown with the Atari TT at computer shows.  The 505 was never seen again...  There was talk of an Atari badged CD-ROM drive for the Atari Falcon, but this was soon dismissed, and Atari said Falcon users could just use "any" SCSI compatible CD-ROM drive instead.

Incidentally, the only Atari CD Player device to actually make it to the end user was the infamous Jaguar CD, produced exclusively for the Atari Jaguar game console. It had a limited production run and unfortunately only a handful of titles.