Abstract: An apparatus and method for transferring a data payload (SPE) from a first substantially SONET signal into a second substantially SONET signal of different frequency is provided. The apparatus has: a circuit for extracting the SPE from the first SONET signal and sending the bytes of the SPE, according to a first clock, to a FIFO for storage; a circuit for obtaining the SPE bytes from the FIFO according to a second clock, for building the SPE into the second substantially SONET signal; and a circuit for comparing the relative byte phases of the first and second clocks. The byte phase comparison circuit serves two functions. In order to avoid read/write conflicts in the FIFO, it generates and sends a signal to the extracting circuit which causes the extracting circuit to change the byte phase (i.e. timing) at which bytes are sent to the FIFO.

Abstract: A single board multiple option card for expanding the versatility of a host computer includes an onboard microprocessor, a digital signal processor and a switched memory device. The switched memory is accessible by the onboard microprocessor and the digital signal processor under the control of the onboard microprocessor. The card further includes an analog signal interface having a plurality of switches, the positions of which are controlled by the onboard microprocessor. As a result, multiple options are provided by varying the positions of the switches. Typically, such options may include: "Invisible Keyboard"; "Voice Command Over Telephone Lines"; "Voice Store and Forward Over the Telephone"; "Voice Record and Playback"; and "Hands-free Telephone".