Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family processors of previous Sun models.
Models are listed in approximately chronological order.
In 1989, Sun dropped the "Sun-4" name for marketing purposes in favor of the SPARCstation and SPARCserver brands for new models, although early SPARCstation/server models were also assigned Sun-4-series model numbers. For example, the SPARCstation 1 was also known as the Sun 4/60. This practice was phased out with the introduction of the SPARCserver 600MP series in 1991. The term Sun-4 continued to be used in an engineering context to identify the basic hardware architecture of all SPARC-based Sun systems.
Sun 4/110, 4/150, 4/260 and 4/280 systems upgraded with the Sun 4300 CPU board (as used in the SPARCserver 300 series) were referred to as the 4/310, 4/350, 4/360 and 4/380 respectively.
The Sun-4 architecture refers to the VME-based architecture described above and used in the Sun 4/100, 4/200, SPARCserver 300 and SPARCserver 400 ranges. Sun-4 support was included in SunOS 3.2 onwards and Solaris 2.1 to 2.4. OpenBSD and NetBSD also will run on the Sun-4 architecture families.
Several variations on the Sun-4 architecture were subsequently developed and used in later computer systems produced by Sun and other vendors. These comprised: