Friday I tried the 1056 version of sparc32 openbios and found that Solaris 8 hangs during the OS initialization (during the second period when the spinning line (-, , |, /, -) occurs).
The last version of openbios I had been using was 1047 which seemed to work Ok. So, I incrementally checked versions 1048-1056. The boot works on all but 1056, so it looks like something with the memory changes in 1055 broke the Solaris 8 boot.
Let me know if you need any specific information about Qemu arguments.
Respectfully, Paul