An emulator schedules emulation threads for DMA emulation and other emulation functions in a time-multiplexed manner. Emulation threads are selected for execution according to a load balancing scheme. Non-DMA emulation threads are executed until their execution time period expires or they stall. DMA emulation thread execution is allowed to execute indefinitely until the DMA emulation thread stalls. The DMA emulation thread prefetches additional adjacent data in response to target computer system DMA requests. Upon receiving a target computer system DMA request, the DMA emulation thread first checks to the prefetched data to see if this data matches the request. If so, the request is fulfilled using the prefetched data. If the prefetched data does not match the target computer system DMA request, the DMA emulation thread fetches and stores the requested data and additional adjacent data for potential future use.