Abstract: A device for enabling detection of a counterfeit optical CD-ROM is disclosed for use in a conventional mastering system. The device includes a signal source for providing a first signal for forming a predetermined defect in a glass master. The device also includes a switch for connecting a recorder of the mastering system to the signal source. In addition, the device includes a decoder for decoding encoded data and address information provided from an input source of the mastering system. Furthermore, the device includes a central processor unit which serves to detect whether a selected address from the decoded data is present. Upon detection of the selected address, the CPU controls the switch to connect the signal source to the recorder to enable the recorder to receive the first signal and form the predetermined defect at the selected address.

Abstract: A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM. Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM. The serial number is read by detecting the defects. The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM.

Abstract: A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM, Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM, The serial number is read by detecting the defects, The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM,

Abstract: A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM. Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM. The serial number is read by detecting the defects. The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM.

Abstract: Serial input/output multiplexing apparatus for bi-directional communication of input status signals and output control signals between remote devices and a programmable logic controller (P.L.C.) over a two-wire, asynchronous communication channel. A remote module includes an input interface circuit to receive input status signals from each of plural input devices, an output interface circuit for transmitting output control signals to each of plural output devices, and a controller for selectively coupling the input interface circuit or the output interface circuit to the two-wire asynchronous communication channel for transmitting serial status information to the communication channel or for supplying to the output interface circuit output control information serially received from the communication channel. A local module includes a local output interface circuit for applying the status information to the P.L.C., a local input interface circuit for receiving control information from the P.L.C.

Abstract: A secure answering machine allows both secure and non-secure information to be recorded by incorporating a digital signal processor (DSP) and both a secure and non-secure RAM. The secure RAM is powered entirely by battery. The battery is then connected to the housing of the answering machine such that when the housing is tampered with, the power from the battery is shut off eliminating all information stored on the secure RAM. The secure RAM is only accessed using an encrypting code.