Simics scripts for starting Niagara Simple machines are located in the [workspace]/targets/niagara-simple/ directory, while the actual configuration scripts can be found in [simics]/targets/niagara-simple/.
The niagara-simple machine is the only configuration distributed. It has an UltraSPARC T1 processor running at 5 MHz, and 256 MB of memory. One, two or all 32 strands (virtual processors/hardware threads) can be enabled. The default configuration can be modified as described in section 3.2. The reason that the memory size, processor frequency and number of strands cannot be changed is that they are hardcoded in binary files used by the OBP.
The following parameters can be set before running the niagara-simple-solaris-common.simics. Other .simics scripts may set some of the parameters unconditionally, and do not allow the user to override them.