Abstract:
In accordance with this invention, matched performance of alternate sourced ASICs is achieved while still allowing for the smallest die size possible from each alternate source fabrication facility. In one aspect of this invention, the width of electrical interconnects (Wm1, Wm2) are adjusted to compensate for differences in capacitances of a given interconnect path in devices fabricated by different fabrication facilities. In another aspect, transistor channel widths (Wpd, Wnd) are adjusted to compensate for differences in capacitances of a given interconnect path in devices fabricated by different fabrication facilities. In yet another aspect of this invention, capacitance is added to the gates of transistors to decrease their speed, when manufactured by an inherently faster process.
Abstract:
A computer having a keyboard unit with a spacebar wherein a trackball module is mounted within the spacebar for ease of access by left-handed or right-handed persons. The trackball module is mounted intermediately of the spacebar. In one embodiment, the trackball module is mounted for movement with a spacebar and in another embodiment, the trackball module is stationary such that the spacebar moves upwardly and downwardly relative to the trackball module.
Abstract:
A modem (12) is incorporated into a laptop computer (10) and directly connected to either a cellular phone (22), a land line (18), or both. The modem is provided with two connectors (14, 16), one for connection with a cellular phone or external DAA (24), the other for connection to a normal land line via an internal DAA (112). The modem selectively enables either the connector for the cellular phone or external DAA, or the connector for its internal DAA. The modem defaults to selecting the cellular phone or external DAA if it is connected, and only if they are not connected selects the internal DAA. These defaults can be overridden by user commands. Further, the modem can independently power down a connected internal DAA, external DAA, or cellular phone to conserve power.
Abstract:
A method and apparatus for operating tightly coupled mirrored processors in a computer system. A plurality of CPU boards are coupled to a processor/memory bus, commonly called a host bus. Each CPU board includes a processor as well as various ports, timers, and interrupt controller logic local to the respective processor. The processors on one or more CPU boards are designated as master processors, with the processors on the remaining CPU boards being designated as mirroring or slave processors. A master processor has full access to the host bus and a second, multiplexed bus for read and write cycles, whereas the slave processors are prevented from writing to any bus. The slave processors compare write data and various control signals with that generated by its respective master processor for disparities. The system includes interrupt controller synchronization logic to synchronize interrupt requests as well as timer synchronization logic to synchronize the timers in each of the master and slave CPUs to guarantee that the master and slave CPUs operate in lockstep.
Abstract:
A method and apparatus for reducing the snooping requirements of a cache system and for reducing latency problems in a cache system. When a snoop access occurs to the cache, and if snoop control logic determines that the previous snoop access involved the same memory location line, then the snoop control logic does not direct the cache to snoop this subsequent access. This eases the snooping burden of the cache and thus increases the efficiency of the processor working out of the cache during this time. When a multilevel cache system is implemented, the snoop control logic directs the cache to snoop certain subsequent accesses to a previously snooped line in order to prevent cache coherency problems from arising. Latency reduction logic which reduces latency problems in the snooping operation of the cache is also included. After every processor read that is transmitted beyond the cache, i.e., cache read misses, the logic gains control of the address inputs of the cache for snooping purposes. The cache no longer needs its address bus for the read cycle and thus the read operation continues unhindered. In addition, the cache is prepared for an upcoming snoop cycle.
Abstract:
Circuitry for drawing lines includes a video memory for storing pixel data and circuitry for generating a sequence of addresses defining a line of pixels in the video memory. A first memory stores a sequence of pattern units corresponding to the generated sequence of addresses. A second memory stores a value indicating a current pattern unit. Writing circuitry writes to the video memory at a generated address responsive to a current pattern unit. A third memory stores a control value which is accessed by update circuitry for updating the second memory to indicate the next pattern unit. The update circuitry may selectively update the second memory to the sequential pattern unit or reset the second memory to a predetermined pattern unit.
Abstract:
A method of determining an object's position and associated apparatus provides positional information in a form that may be conveniently communicated to a computer to calculate the object's position. In a preferred embodiment, representatively incorporated in a computer keyboard, a method of determining an object's position includes forming an optical grid of reflected beacons and detecting an obstruction of the reflected beacons. A preferred embodiment apparatus utilizes a single light source to detect an object's position in two dimensions.
Abstract:
An integrated multi-color drop-on-demand type ink jet printhead (12). The printhead includes a main body portion (14) and a plurality of generally parallel, longitudinally extending ink-carrying channels (36) arranged into at least two channel arrays (35a-35d). A manifold (21a-21d) corresponding to each of the at least two channel arrays and in communication with each of the ink-carrying channels (36) of the corresponding array is formed in the main body portion (14). Ink is supplied to each of the at least two channel arrays from a corresponding ink source (18a-18d), each of which is filled with a different color of ink.
Abstract:
A single side interconnectable ink jet printhead and an associated method for manufacturing the same. The ink jet printhead includes a lower body portion (14) having a plurality of conductive sections (16) mounted to a top side (14a) of the lower body portion (14) and a corresponding plurality of conductive pins (20) projecting from a bottom side (14b) of the lower body portion (14). Each of the conductive sections (16) is electrically connected to the corresponding one of the conductive pins (10). A bottom side surface of each one of a plurality of generally parallel, longitudinally extending first intermediate body portions each formed of an active piezoelectric material poled in a first direction parallel to the top side surface of the lower body portion is conductively mounted to a portion of the top side surface of the lower body portion. A bottom side surface of each one of a plurality of generally parallel, longitudinally extending second intermediate body portions, each formed of an active piezoelectric material poled in a second direction opposite the first direction is conductively mounted to a top side surface of a corresponding one of the first intermediate body portions and a bottom side surface of an insulative upper body portion is conductively mounted to a top side surface of each of the plurality of second intermediate body portions.
Abstract:
The operation of U or UU type drop-on-demand ink jet printheads are enhanced by selectively incorporating therein volume modifying tapers in the ink carrying channels, means for electrically isolating portions of the actuators thereof, and/or forming a variable layer of conductive material between the upper and lower sidewall portions therefor.