Hi, dosbox-0.65 is running pretty fine on my sparc. I had to install it with ACCEPT_KEYWORDS='~x86', because it's masked for sparc. Why so? I have to admit that my gcc version is 4.1.1, so I'm not using the stable sparc tree.
Check out the SPARC FAQ from the Gentoo documentation project as to why something isn't keyworded. This seems to work OK using the regular toolchain, so I've added ~sparc keywords. Thanks for the bug report.