SunPC, the "PC" (486) card for Sun Sparcstations requires software to run.
Although I understand this has copyright, I believe it would be similar to Solaris 2.3 -> Solaris 2.6 (which has similar release date and is hosted here).
SunPC 4.1 runs on Solaris 2.3/2.4 (software and patches included)
SunPC 4.2 runs on Solaris 2.5/2.6 (software, documentation and patches included).
The product was dropped soon-after 4.2 release.