ARINC Specification 844, prepared in two parts, defines the requirements of a Target Data Loader (TDL) from the target hardware point of view. Both parts are based on two data loading standards: Part 1 clarifies ARINC Report 615-3: Airborne Computer High Speed Data Loader, Part 2 clarifies ARINC Report 615-4: Airborne Computer High Speed Data Loader. ARINC Report 615 was originally written from the data loader point of view. It is important that a target designer have a general understanding of the operation of a data loader in its modern implementation. Equally important is the need for data loader manufacturers to understand the standardized implementation requirements and supported subset of ARINC 615 features that are defined in ARINC 844, Parts 1 and 2. Therefore, ARINC Specification 844 is expected to provide value to both data loader and target implementers.