Abstract: Described herein is a system for transferring a binary data stream in a serial edge-based transmission format between a computer and a portable device such as the Timex.RTM. Data-Link.TM. watch. In the edge-based format expected by the Data-Link.TM. watch, individual data bits have first and second binary values which are represented by the presence or absence of signal edges at mark times which occur at a pre-selected bit rate. The system includes a computer having a digital output line which can be turned on and off by the computer at any time. The computer also has an internal timer which is programmed to generate timing signals at a frequency which is an integer multiple n of the pre-selected bit rate. An LED is operably connected to the digital output line so that the computer can switch the LED on and off at any time through the digital output line. An application program runs on the computer.

Abstract: A carrier for a wrist instrument when it is removed from the wrist band comprises a case made in two pieces of identical construction which slide together and house the wrist instrument and its attachments. The two carrier sections each have a tongue extending across a parting line which is received in a mating channel on the other carrier section. Additional guide pins and recesses hold the assembly in alignment. A holster for the assembled carrier sections cradles the assembly securely and includes a belt clip for attaching the holster to a belt.

Abstract: Accessory for a laptop computer with LCD display which is connected to the laptop serial communications port and optically transmits data to a portable information device, such as a wristwatch designed to receive data as sequential pulses of light. The accessory includes a microcomputer with an RC timebase which is calibrated each time it is used by a special internal program, so that the input baud rate to the accessory matches the communications baud rate of the data received from the laptop. The internal program also permits selection of an output baud rate for the optically transmitted data.