The Macintosh Centris 660AV, the last computer to use the Centris name.
Macintosh Centris is a line of Macintosh computers, introduced in 1993, that were built around the Motorola 68LC040 and 68040 CPUs. The name was chosen to indicate that the consumer was selecting a Macintosh in the center of Apple's product line: lower performance (and price) than the Quadra computers, but higher performance (and price) than the Performa computers of the time. The name echoes other "neoclassical" prestige branding trends introduced at the time such as Lexus and Acura.
The Centris 610 uses a 20 MHz 68LC040 CPU, which has no math coprocessor functions. It used a new "pizza box" case that was intended to be placed under the user's computer monitor. This case was later used again in the Quadra 610 and Power Macintosh 6100 lines of computers, and when these later computers were introduced, Apple offered consumers a product upgrade path by letting them buy a new motherboard. Apple's motherboard upgrades of this type were considered expensive, however, and were not a popular option. The Centris 610 also provided the base for the Workgroup Server 60.
The name "Centris" was soon considered to be confusing to customers, and was abandoned. The Centris 610 and 650 were replaced about six months later by the Quadra 610 and 650 models, which kept the same basic case and design but raised the CPU speeds from 20 MHz and 25 MHz to 25 MHz and 33 MHz respectively; while the Centris 660AV was renamed to Quadra 660AV without any actual design change. These Macs also existed during Apple's transition from auto-inject floppy drives to manual-inject drives. This is why there are two different styles of floppy drive opening on these models. Some later Centris 660AV Macs have manual-inject floppy drives, so this change was not exactly concurrent with the name change.