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We present maps of the hard X-ray (2-20 keV) sky in four overlapping energy bands. The data are from the HEAO-1 A2 all sky scanning experiment. Though these data were collected in 1977-79, this survey remains unequalled by any other existing or approved mission. We discuss public access to these data (through the GSFC High Energy Astrophysics Science and Archival Research Center) and issues related to use of these data including exposure, statistical and systematic uncertainties, point source response function, and energy response.