Abstract: A method and an apparatus for re-creating a trace of instructions from an emulated instruction set when running on hardware optimized for a different instruction set, such as IA-32 instructions running on an IA-64 machine, are disclosed. An execution trace buffer is created that maintains desired information about instructions as they are executed and retired. The invention may be configured such that certain desired information helpful to debugging the system may be written to the buffer as the instructions are retired. This information may include the addresses of sequential or branch instructions, or other relevant information that can be gathered continuously and non-intrusively as instructions are executed. The information may be read from the buffer and output in a machine-visible form at the user's convenience.