1.2 History

The first version of the BlueGene emulator was written in Charm++, a parallel object language, in fall 2001. The second version of the BlueGene emulator was completely rewritten on top of Converse instead of Charm++ in spring 2002. While the API supported by the original emulator remains almost the same, many new features were added. The new emulator was implemented on a portable low layer communication library - Converse, in order to achieve better performance by avoiding the cross layer overhead.

Charm++ was ported to the emulator in 2002, providing the first parallel language model on top of the emulator.

A performance simulation capability was added to the emulator in spring 2003. The new simulator was renamed to BigSim at the same time. During the same year, we developed a POSE-based postmortem mode network simulator called BigNetSim. In fall 2006, we renamed BigNetSim as simply BigSim simulator.

In the following sections, we will first describe how to download and compile the BigSim system (Section 2). Section 3 describes the BigSim Emulator and the low level machine API in detail.