Abstract: Reproduction apparatus is disclosed having at least one image signal generator, a multiple page buffer memory for storing the image signals, and a writer for forming images from the page buffer memory. Upon the occurrence of a malfunction in the writer, operation of the image signal generator is continued only until the first to occur of (a) all of the original pages have been stored in the multiple page buffer memory or (b) the multiple page buffer memory is filled. Upon the occurrence of a malfunction in the signal generator, operation of the writer is continued until the next page to be written has not been stored in the buffer memory.

Abstract: An electrophotographic copies having a document scanner which determines the location of registration marks on the platen. The scanner is initially operated in a calibration mode without a document on the platen. The platen is scanned and the data obtained is processed to determine when transitions from low to high density occur. These occurrences are translated to scanner locations to obtain the locations of the edges of the registration marks or guides, and the locations are stored in memory. In subsequent scannings of documents, only data within the determined locations of the registration edges is stored in memory.