Abstract: Methods and apparatus are described for providing a time-based warning indicating that the energy capacity of a primary energy source of a battery-powered computer has discharged to a low level, and using residual energy of the primary energy source to perform at least one pre-cutoff function. The time-based warning ensures that the warning is provided in a timely manner by overcoming problems caused by analog to digital converter voltage measurement accuracy limitations and flat battery operating voltage versus discharge curves. The primary energy source can be a rechargeable battery, which can also be the sole energy source for the computer. The battery provides power to operate the computer until the battery voltage discharges to the cutoff voltage. The methods and apparatus provide advantages because they reserve the residual energy in the battery to perform at least one pre-cutoff function within a first duration before the battery discharges to the cutoff voltage.

Abstract: A handheld computer having a housing with a midframe construction is described. The housing includes a front shell and a back shell coupled to a midframe. The handheld computer also includes two accessory slots for a stylus or other devices on the left and right sides of the housing. The handheld computer also includes an infrared port which is an integral portion of the housing.

Abstract: A handheld computer having a housing with a midframe construction is described. The housing includes a front shell and a back shell coupled to a midframe. The handheld computer also includes two accessory slots for a stylus or other devices on the left and right sides of the housing. The handheld computer also includes an infrared port which is an integral portion of the housing.

Abstract: A computer cradle is described that includes a stylus holder that is at least partially light transmissive. The light transmissive material of the stylus holder transmits to a user light generated within the computer cradle. The stylus is seated in a funnel-shaped cavity formed in a stylus holder oriented nonperpendicularly to a cradle housing, so that a stylus supported by the stylus holder is more easily accessible.

Abstract: Systems and methods are described for detachable antennas. A wireless communications device includes: a cam body defining a rotation axis, the cam body including a retaining zone having a snap-fit receptacle; a signal pin including a first signal pin end and a second signal pin end; an antenna conductively coupled to the first signal pin end; and a key pin that extends from the signal pin, the key pin having a first key pin end and a second key pin end, and being snap-fit into the snap-fit receptacle. The systems and methods provide advantages in that the detachable antenna is easily replaced without tools.

Abstract: A method and apparatus for multiplexing time-shared base stations between a plurality of radio communication systems in a cellular communication system. Each radio communication system in the cellular system is assigned a limited unique set of frequencies for communication therein. Base stations in the cellular system are synchronized to a common time base and frequency reuse is achieved by time-sharing the frequencies via allocated time slots. Base stations activated to communicate in a first radio communication system and using the same frequencies that may interfere with each other are activated in the first system only during selected time intervals while same-frequency base stations nearby are deactivated in the first system. The deactivated base stations are then in turn activated in the first system while previously activated same-frequency base stations nearby are deactivated.

Abstract: In a personal communications device having a touch sensitive display screen, text may be marked by a user to be used with different applications. In particular, to begin marking, a user has to maintain his touch at a location on the screen for a short predetermined period of time until the system detects that the position is held over the same character for a delayed period, at which time the system beeps to provide an indication that there has been a change of operation mode. The marking mode continues in operation until the user removes his contact from the touch screen. Thus, text over which the contact point passes after the initiation of the marking mode is marked, until the user removes his contact point from the touch screen. A second beep is sounded to alert the user of the termination of the marking mode, and the appearance of a menu of operations on the screen. The menu of operations echoes the marked text for user confirmation.