John Deere Harvester Works Product Engineering developed a combine simulation computer program called HarvesTrainer. This is a combine operator training aid that will run on many personal computers. It covers both corn and small grain harvesting within the range of combines that John Deere presently makes. HarvesTrainer has been used and reviewed by various members of the John Deere engineering, service, and marketing departments and has received a very positive response. In prototype form it was used at an infield combine school in the fall of 1984. It was then released to John Deere service and training personnel and is now available as a market item. People who used the program have felt it to be very helpful in assisting them to understand combine operation.