Creating a midpoint between the Mac II line and the Quadra series, the short-lived Centris models were introduced in February 1993. The Centris 610 introduced a new case style, one that would later be used for the Centris 660av and Power Mac 6100 .

“Going along with the auto-marketing trend toward meaningless names that sound important, Apple’s new Centris line will serve as the company’s mainstream, midlevel computers.” MacUser, April 1993 (Apple names included Quadra, Performa, and Centris.)

Unlike either the Mac II or previously existing Quadra models, this Mac has a power switch on the front and cannot be turned on or off using the power key on the keyboard. (Many users more familiar with DOS hardware mistook the power switch for a floppy eject button – although it didn’t take long to discover what the button really did.)

Specs (via Low End Mac)

• Cpu: 20 MHz 68LC040
• Fpu: none, 68LC040 can be replaced with 68040 CPU
• Performance: 9.7 est., relative to SE; 0.80, Speedometer 4
• Ram: 4 MB on motherboard, expandable to 68 MB using 80ns 72-pin SIMMs; motherboard has 2 SIMM slots, which can be filled independently; can use 4 MB, 8 MB, 16 MB, and 32 MB SIMMs. If SIMMs are not the same speed, faster SIMM should be in bank 0 (frontmost slot).
• Rom: 1 MB
• L2 Cache: optional, PDS
• Hard Drive: 80 or 230 MB
• Video: 512 KB VRAM, expandable to 1 MB 512 x 384 @ 16-bit 640 x 480, 800 x 600, 832 x 624: 8-bit @ 512 KB, 16-bit @ 1 MB 832 x 624, 1024 x 768, 1152 x 870: 4-bit @ 512 KB, 8-bit @ 1 MB
• Addressing: 24-bit or 32-bit
• Gestalt Id: 52
• Upgrade Path: Quadra 610 , Power Mac PDS card , Power Mac 6100 (requires some case modification)
• Adb Ports: 2
• Scsi: DB-25 connector on back of computer
• Pram Battery: 3.6V half-AA
• Weight: 14 lb.
• Din-8 Serial Ports: 2
• See: Online resources and links for the Centris 610