Abstract: Method for continuing the operation of a machine despite the malfunction of a nonessential feature. If the determination is made that a feature program is nonoperable, another check is made by sensing a corresponding flag to determine whether the feature is essential to the continued operation of the machine, and, if not, allows the machine to continue operation without the feature.

Abstract: A copy production machine, or other semiautomatic operator-involved machine, logs operations data and error data during normal operations into a nonvolatile store. Logging is categorized for facilitating diagnostics and maintenance of the machine. During a maintenance mode, log scanning methods enable efficient retrieval of the logged data via a keyboard entry system plus manual actuation of other switches used for other purposes during the normal copy production.

Abstract: Expandable memory system having add-on modules beginning at fixed address boundaries, e.g., 2K (K=1024), and having verification and authorization features. A non-volatile memory stores a bit corresponding to each 2K memory boundary. When an add-on program is authorized at a particular boundary address, the corresponding bit is set. The base program checks each bit and, if it is set, reads the first location of the corresponding add-on program. If the data read from the new module matches some reference, e.g., the boundary address itself, then program control branches to the add-on program. Additional verification features include cyclic redundancy checks of the added code. Alternative operation includes branching to a verified add-on program that tests its own authorization bit which, if reset, causes a branch to the next verified add-on program, and so on.

Abstract: Sheet collator apparatus having means for recovery from collating errors. Moving between two adjacent bins without feeding a sheet, feeding two sheets into one bin, or feeding a sheet while the feeder is moving are errors that are detected and corrected. An error is corrected by homing the deflector and repositioning it at the correct bin before restart. The described embodiment includes two collators, i.e., tandem units.

Abstract: Copy production machine under program control selectively interleaving copy separation sheets between successive copy jobs. The copy separation sheets can be supplied from the same copy sheet supply source as the copies being produced or from an alternate supply source. The number of separation sheets supplied is a predetermined relationship between the number of copy receiving bins in an output receiving the copy separation sheets and the number of copies to be produced from a source. The effective capacity of a collator is extended by such interleaving using a programmable control that talies copies made versus copies selected greater than the capacity of a collator such that the collator job is automatically segmented.

Abstract: Copy production machine selectively interleaves copy separation sheets between successive copy jobs, subjobs, or job portions. The copy separation sheets can be from the same copy sheet supply source or from an alternate source. The supplied copy separation sheets need not be operated upon by the copy production machines, i.e., receive an image. Such sheets may be preimaged if so desired. When copy sheet supply means has different size copy sheets, the separation mode may be inhibited. The number of separation sheets supplied depends on the number of copy receiving bins in an output means and the number of copies produced from a single image. The effective capacity of a collator is extended by the use of separation sheets.

Abstract: Copy machine having provisions for separately addressing and independently exercising individual machine components for maintenance purposes. There are also provisions for addressing sensory components individually and for providing a visual indication of the state of the addressed element so that its proper operation can be verified. In addition to operability indications, the address of the individual machine component being exercised or the sensory component being tested can be displayed.

Abstract: A copy production machine, such as a transfer electrographic copier, picks copy sheets for receiving images during a transfer operation. On rare occasions a sheet may not be successfully picked. Instead of turning the machine off and requiring manual intervention for a restart, the machine automatically retrys to repick the sheet of paper a predetermined number of times. If during such retry the pick is successful, then the copy production resumes automatically; if not, the machine is turned off after the predetermined number of cycles. During each machine cycle having an unsuccessful pick, protective actions are taken to insure that toner does not contaminate the machine and certain other actions do not provide a fire hazard. All retries are logged for maintenance assistance.