｢ Solaris 2.1 for x86, also known as SunOS 5.1, was Sun’s first entry into the PC market (technically it was SunSoft, a subsidiary of Sun Microsystems, who released Solaris). However, it wasn’t Sun’s first x86 operating system. In the late 1980s, Sun sold 386i workstations based on Intel 386 processors. The 386i workstations were not PC compatible and ran SunOS 4.0, a BSD UNIX derivative with many custom Sun enhancements ｣
https://www.os2museum.com/wp/pc-unix-history/solaris-2-1-for-x86/
