Abstract: A coded logical interrupt signal is sent between system or subsystem units in a data processing system. The logical interrupt is sent by a sending unit, that requests the interrupt, and is sent to a receiving unit that the sending unit wishes to interrupt. These coded logical interrupts are accumulated in the receiving unit. When the receiving unit is actually physically interrupted by control of the processor in the unit, all logical interrupts that have been accumulated are processed. The logical interrupt may be coded to indicate sending unit, that is the source of the interrupt, and the action being requested by the sending unit. If the interrupt includes only source information, the action information is sent separately by the sending unit to memory in the receiving unit. If the interrupt includes both source identification and action information, the receiving unit can interpret source and action directly from the interrupt.

Abstract: An architecture is disclosed for communication of remote devices to a digitizing display. The architecture includes a contact sensing erasure mechanism and a position sensing erasure mechanism whose outputs are multiplexed for transmission from the stylus to an antenna located proximate to the digitizing display. The digitizing display will erase text or graphics data in a pen-based computer system in response to the stylus. A calibration method provides improved accuracy for the erasure function.

Abstract: A method is disclosed for managing the communication of data packets between a mobile data radio terminal and a plurality of fixed base stations in a data communications network. In a system of a plurality of base stations (each including a set of cellular telephone voice transceivers), wherein a first and second base stations are coupled through a home mobile data gateway (MDG) to the data communications network and a third base station is coupled through a server mobile data gateway to the data communications network, a method and apparatus which establishes in the home mobile data gateway, a forwarding address to a server mobile data gateway, sends forwarding information from the home mobile data gateway to the server mobile data gateway, and allocates with the server mobile data gateway, a new channel at the third base station, for the mobile data radio terminal.

Abstract: A method and system to recognize input events from a plurality of input devices. Each input device is coupled to a device driver or similar device specific code and a recognition provider. Upon attachment to the system, the recognition provider registers the known input events which the input device is capable of transmitting at the recognition subsystem. The recognition subsystem sends an identifier back to the recognition provider for each registered input event. When the recognition provider receives one or more input signals from the input device which are recognized as an input event, the provider sends the identifier to the recognition subsystem. The input event is transmitted to a process running on the system which may interpret the input event or request translation by the recognition subsystem. The invention is useful to introduce new input devices to a system without requiring modification of the existing processes.

Abstract: A system and method is disclosed for predicting which 3270 Attention IDentifer (AID) keys are likely to be requested by the user, based upon the prior key sequences and the actual screen displays. If the predicted key is the same as the actual key, then the 3270 screen is refreshed accordingly. If the predicted key is not the same as the actual key, then the actual AID key request is sent and the system will synchronize itself to get back to where it would have been, but for the sending of the predicted key. The system is table driven using an AID key History Buffer, a Screen S6gnature History Buffer, an AID key Probability Table, and a Screen Signature Application Table.

Abstract: A personal communicator has a touch sensitive overlay coupled with a liquid crystal display (LCD). The communicator has two external (non-screen) up/down buttons for adjusting the volume of a cellular phone speaker. These volume buttons are also used to allow the user to adjust contrast. In accordance with one operation, contrast is adjusted in response to the user touching a predetermined area of the screen at the same time as one of the up or down buttons is actuated. In accordance with another operation, contrast is adjusted in response to the user first pressing both speaker volume buttons to enter a contrast adjustment mode, and thereafter pressing one or the other of such buttons, to increase or decrease contrast as desired.

Abstract: An architecture is disclosed for improved tilt detection for a radiative pickup stylus. The architecture includes a contact sensing mechanism and a coaxial conductor assembly which provides both position measurement and tilt sensing measurement features. By using the contact sensor to establish a calibration for the position and tilt detection elements, an improved, highly accurate position and tilt sensing capability is provided for radiative pickup stylus for a digitizing display.

Abstract: Methods and apparatus are set forth which enable a radio frequency data communications network (1) to perform decentralized uplink network control functions (decentralized away from the centralized general communications controller (GCC) level of the network hierarchy); (2) to minimize, or in some cases eliminate, the overhead expended in making power lever (signal strength) determinations and assessments at both the GCC and base station levels of the network hierarchy (for the purpose of managing uplink communications); and (3) to allow individual subscriber radios (terminals) to dynamically determine the most desirable base station to communicate with when exchanging information a host computer via a shared RF communication channel (the link between a terminal and the base station).

Abstract: A Cellular Data Network (CDN) identifies, collects and utilizes otherwise unused or unusable air time, in an existing Advanced Mobile Telephone System (AMPS). A Digital Cellular Overlay Network (DCON) is provided for performing CDN utilizing an underlying AMPS, where the DCON is transparent, with respect to the AMPS, and takes full advantage of existing AMPS equipment to keep the cost of performing CDN to a minimum. The resulting digital network may be used for high speed non-interfering data communications, i.e., data communications that do not degrade the underlying system's capacity and capability (qualitatively) to handle voice traffic. Expanded use of well-known radio control signals, in particular "busy bits" and "dotting sequences," provides a DCON capable of performing CDN in both a reliable and flexible manner.

Abstract: A method and apparatus for efficiently distinguishing between different types of input signals simulated by a pointing device coupled to a multi-tasking computer system. The pointing device may be a stylus, finger or other device that moves across the surface of a touch screen or the like to generate positional information. Depending on the response of a delay timer, the motion of the pointing device is recognized by software application programs as input information either from a mouse or from a gesture or a handwriting input mode. If motion cessation across the screen is detected with a predetermined time-delay period, the system accepts the input information in a mouse-emulating mode. If motion is detected within the predetermined time-delay period, the timer is reset. Thus, the system overhead associated with managing the timer can be reduced because the timer is periodically reset and need not be reset after each movement of the pointing device as in the prior art.

Abstract: A digital communication network has a plurality of remote terminals (RTs) which communicate with a plurality of base stations (BSs) by radio links operating at a single frequency. Each RT monitors the signal strengths of outbound messages and keeps an ordered table indicating which BSs produce the highest strength signals. At sign-on, an RT sends a message to the BS at the top of the list. The message includes the first predetermined number of entries at the top of the list. Each BS monitors the number of RTs it can hear and the number of users attached to each BS. The BS to which the sign-on message is sent then decides on the basis of signal strength, number of users attached, and BS coverage which BS should be attached to the particular RT and then notifies a communications controller. Such decision thus levels the workload. Each RT monitors errors and requests re-evaluation of attachment when the error rate for the BS to which it is attached exceeds a predetermined value.

Abstract: A battery-powered magnetic pen has an oscillator for generating a magnetic field at a contact frequency and a proximity frequency. The oscillator is connected to a resettable timer. The pen also includes a tip switch that is actuated in response to the pen being brought into engagement with an object and disengaged from the object. The tip switch is connected to a pulse generator and to the oscillator. Each time the pen is brought into engagement with an object, the pulse generator resets the timer to initiate the timing of a time out period. Assuming the oscillator is off, the first time the pen contacts an object, the resetting causes the oscillator to be turned on. So long as the oscillator is on, the opening and closing of the tip switch causes the oscillator to switch between the contact frequency and the proximity frequency. Should the timer reach the end of a predetermined time out period, the oscillator is shut off.

Abstract: A battery operated computer includes a battery having a plurality of serially connected banks of battery cells that are monitored during operation of the computer to detect a nearly depleted battery bank and a fully depleted battery bank. The computer also includes a plurality of microprocessors including a host or system processor, a service processor and a power subsystem processor. When a nearly depleted battery bank is detected, the power subsystem processor is interrupted and it sends a message to the service processor which in turn interrupts the host processor. An interrupt handler then powers down the system. When a fully depleted battery bank is detected, the battery is immediately disconnected and the system is shutoff to prevent polarity or cell reversal.

Abstract: A battery-powered, magnetic-pen oscillator includes a circuit having a first transistor arranged in a common emitter configuration. A feedback loop includes a transformer and the transistor that produce a loop phase shift of zero degrees and a loop gain of one to cause oscillation, and additionally creates the magnetic field emitted by the pen. A second transistor provides current mirror biasing for the first transistor and determines the amount of current flowing through the first transistor.

Abstract: A digitizer tablet computer has a host processor connected to a service processor which, in turn, is connected to a digitizer controller and to a power subsystem microcontroller. A battery supplies the primary power for operating the computer but the computer is also connectable to an external source of DC power to charge the battery and to operate the computer when it is not running on battery power. The service processor includes a battery gauge the contents of which indicate how much power is left in the battery and how much time remains at the current rate of power consumption before the power runs out. The amount of remaining power in the gauge is determined by keeping track of power consumed, power added, and power lost during off periods. The use of the second derivative of a voltage versus time discharge curve creates a point from which relative accurate estimates can be made of how much longer the computer can be operated.