Sun-3 is a series of UNIX computer workstations and servers produced by Sun Microsystems, launched on September 9, 1985.^[1] The Sun-3 series are VMEbus-based systems similar to some of the earlier Sun-2 series, but using the Motorola 68020 microprocessor, in combination with the Motorola 68881 floating-point co-processor (optional on the Sun 3/50) and a proprietary Sun MMU. Sun-3 systems were supported in SunOS versions 3.0 to 4.1.1_U1 and also have current support in NetBSD and Linux.^[2] It used to be supported by OpenBSD but the port was discontinued after the 2.9 release.^[3]

Models are listed in approximately chronological order.

(Max. RAM sizes may be greater when third-party memory boards are used.)

• 
  Original Sun-3 CPU board
• 
  Original Sun-3 4 MB memory board with Sun-3 SCSI daughter board
• 
  Sun 3/50 CPU board with Helios 4 MB memory expansion

In 1989, coincident with the launch of the SPARCstation 1, Sun launched three new Sun-3 models, the 3/80, 3/470 and 3/480. Unlike previous Sun-3s, these use a Motorola 68030 processor, 68882 floating-point unit, and the 68030's integral MMU. This 68030-based architecture is called Sun-3x.

Sun 3/260s upgraded with Sun 3400 CPU boards are known as Sun 3/460s.

Sun timeline

• Sun 3 Motorola-based systems
• Sun-1
• Sun-2
• Sun386i
• Sun-4
• SPARCstation