The term Digitized Sky Survey originally referred to the publication in 1994 of a digital version of an all-sky photographic atlas used to produce the first version of the Guide Star Catalog. For the northern sky, the National Geographic Society - Palomar Observatory Sky Survey E-band (red, named after the Eastman Kodak IIIa-E emulsion used), provided almost all of the source data (plate code XE in the survey). For the southern sky, the J-band (blue, Eastman Kodak IIIa-J) of the ESO/SERC Southern Sky Atlas (known as the SERC-J, code S) and the quick V-band (blue or V in the Johnson-Kron-Cousins system, Eastman Kodak IIa-D) SERC-J Equatorial Extension (SERC-QV, code XV), from the UK Schmidt Telescope at the Australian Siding Spring Observatory, were used. Three supplemental plates in the V-band from the SERC and Palomar surveys are included (code XX), with shorter exposure times for the fields containing the Andromeda Galaxy, the Large and the Small Magellanic Cloud. The publication of a digital version of these photographic collections has subsequently become known as the First Generation DSS or DSS1.