Intel® Simics® Simulator 7 is binary compatible with recent models from version 6 but it is not directly compatible with neither version 4.8 nor 5. However, the simulator supports the same structure of installation and multi-user configuration, so upgrading should be simple.
For version 4.8, select the 4.8 API to get access to deprecated parts of the API. This is described in the Simics Migration Guide.
For both version 4.8 and 5, some Python source code may have to be updated before recompiling.
Version 7 releases are binary compatible, so nothing special needs to be done when upgrading. Unless specifically mentioned in their Release Notes, add-on packages should work with any installation of Simics Base, version 7. A more detailed description of compatibility issues for user-created modules is available in the Simics Migration Guide.