Macintosh Quadra 610

The Macintosh Quadra 610, originally sold as the Macintosh Centris 610, is a personal computer designed, manufactured and sold by Apple Computer from February 1993 to July 1994. The Centris 610 was introduced alongside the larger Centris 650 as the replacement for the Macintosh IIsi, and it was intended as the start of the new midrange Centris line of computers. Later in 1993, Apple decided to follow an emerging industry trend of naming product families for their target customers – Quadra for business, LC for education, and Performa for home – and folded the Centris 610 into the Quadra family.

The 610 is the second Macintosh case design (after the Macintosh LC family) to use a pizza box form factor; it was later used for the Quadra 660AV and the Power Macintosh 6100. A server variant, the Workgroup Server 60, was introduced in July 1993 with a 20 MHz processor, which received the same 25 MHz upgrade in October.

In February 1994, a "DOS Compatible" version of the Quadra 610 was introduced as a way for Apple to judge whether the market would be interested in a Macintosh that could also run DOS, providing this DOS compatibility using an additional i486SX processor running at 25 MHz on a card installed in the Processor Direct Slot of the machine. The product was deemed a success by Apple, selling all 25,000 units that were produced within months of its launch. Having proven the demand for such capabilities, Apple developed a successor for the Power Macintosh 6100 and exhibited a "technology demonstration" of a card for the Quadra 630, although Apple indicated that follow-up products for earlier models might be delegated to third-party suppliers.

The Quadra 610 was replaced with the Quadra 630 in July 1994, and the Workgroup Server 6150 replaced the Workgroup Server 60 as Apple's entry-level server offering.