Patents Assigned to International Computers Ltd.
  • Patent number: 4697234
    Abstract: A data processing system is constructed from processing modules (e.g. LSI chips). Each module contains storage circuits which are connected together, for test and diagnostic purposes, to form a plurality of shift register paths in parallel between common input and output terminals. The common terminals on all the modules are connected to a diagnostic unit by way of common input and output lines. In operation, a first control message from the diagnostic unit is shifted into a master shift register, connected to the common input line, and this causes one of the modules to be selected. A second control message from the diagnostic unit is then shifted into a control shift register in the selected module, and this causes one of the shift register paths in that module to be selected. Test data can then be shifted into the selected path from the diagnostic unit.
    Type: Grant
    Filed: June 30, 1986
    Date of Patent: September 29, 1987
    Assignee: International Computers, Ltd.
    Inventors: Alan Spillar, Peter L. L. Desyllas
  • Patent number: 4441159
    Abstract: A digital adder circuit for binary-coded-decimal operation, comprising a set of multiplexers (11) which are conditioned with a pattern of input bits causing them to form an intermediate result (IR) equal to the sum of the two operands (A0-A3, B0-B3) plus a correction value of six. The intermediate result is adjusted by subtracting the correction value if the intermediate result is less than sixteen. The circuit is also operable in a pure binary mode, or can be made to perform various logical operations.
    Type: Grant
    Filed: July 7, 1981
    Date of Patent: April 3, 1984
    Assignee: International Computers Ltd.
    Inventor: Peter A. Hart
  • Patent number: 4382701
    Abstract: A wire matrix printing head moveable along a printing line on a record medium is described in which a ring of wire-selection electromagnets are grouped about the wire guiding arrangement, the electromagnets each having a basic yoke assembly with a pair of limbs each able to support a separate energising coil. The electromagnet armatures are supported by a common frame having a plurality of finger-like structures, one for each armature, on which the armatures are respectively pivoted. The printing wires are spring loaded into their restored positions and abut their respective armatures, which are supported in their respective unoperated positions each by an adjustable resilient backstop. The printing wires are supported in guides so that they are arranged in two columns, both the columnar pitch and the pitch of nominally adjacent wires in the columns being of the order of the wire diameter.
    Type: Grant
    Filed: May 27, 1981
    Date of Patent: May 10, 1983
    Assignee: International Computers Ltd.
    Inventor: Keith B. Davenport
  • Patent number: 4380797
    Abstract: A data processing system has a two-level storage system in which data items are copied from a main store into a smaller, faster slave store on demand. The mapping of the main store on to the slave store is a many-to-one mapping so that situations will occur where two required data items cannot both be present simultaneously in the slave store because they map on to the same location. The system has special logic which detects this situation and, upon detection, temporarily suspends the use of the slave store and instead uses a smaller first-in first-out area of storage.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: April 19, 1983
    Assignee: International Computers Ltd.
    Inventors: Peter L. Desyllas, Barry G. Radley, Alasdair Rawsthorne, John R. Eaton, John E. Murray