摘要:
A plurality of trap save areas are linked to form a pool of such areas from which an area may be loaded with context from various sources in response to a trap condition, such as the addressing of unuseable memory, the loaded area unlinked from the pool, and various pointers changed to reflect such unlinking. The unlinked area is associated with the process which was executing at the time of the occurrence of the trap condition by effectively being coupled to the interrupt level of such process. Independent of the interrupt level, a trap handler routine, specific to the nature of the trap condition, is executed following which the unlinked area is returned to the pool and the various pointers changed to reflect such return.
摘要:
A data processing system includes a microprogram controlled central processing unit that executes instructions. The instruction words include a data type field for identifying the type of operand processed during the execution of the instruction. The data type field signals and a number of control signals are applied to the address terminals of a read only memory. The read only memory output signals are tested by microwords of a microprogram to branch to firmware routines to process the operand type.
摘要:
A first bank or a second bank of storage locations of a control store of a data processing system is enabled in response to one of a plurality of test signals received as parallel inputs by two multiplexer devices. Only one of the multiplexers is enabled at a given time in response to the polarity of one of the test signals selected from the inputs of the multiplexer devices.
摘要:
One or more queue structures in a data processing system may include a threaded list of frames which are enqueued or dequeued from the list in accordance with four instructions wherein each list is tied to a so-called lock or control frame with synchronization for multiple processing units. Multiple lock frames and accordingly multiple lists of frames may be coupled in the system for the purpose of accomplishing the various tasks necessary.
摘要:
In a data processing system a cache memory comprises level one and level two even and odd data stores and level one and level two even and odd directory stores. The directory stores include a plurality of storage locations for storing the most significant bits of the address numbers associated with the data words stored in the level one and level two even and odd data stores. The level one and level two even and odd directory stores are addressed by the least significant bits of the address numbers. Comparator circuits compare the high order bits of an address number supplied in a memory request to the high order bits stored in the level one even and odd directory stores at storage locations identified by both the low order bits of the address supplied in the memory request and the low order address bits incremented by one. A hit detector circuit determines whether one, both, or none of the requested words are stored in the cache memory by analyzing the outputs of the comparators.
摘要:
A binary arithmetic unit performs arithmetic operations on binary coded decimal (BCD) operands by converting the BCD digits to hexadecimal excess 3 digits, generating hexadecimal excess 6 partial product digits and modifying selected excess 6 partial product digits to generate a BCD result.
摘要:
An assembly for use by a surveyor having a ruler and an apparatus for securing the ruler to a surveyor's pole. The ruler has a retractable tape and a belt clip. The apparatus for securing the ruler to a pole includes a cradle sized to retain the ruler, a stop member, a planar wall member and attachment members for securing the apparatus to a pole. By securing the ruler to a pole, a single person may complete measurements which previously required two people. The tape of the ruler includes measurements which are inverted with respect to the tenth of a foot for easier reading.
摘要:
A method and apparatus pertaining to a firmware control unit for detecting when such control unit is not behaving properly. The control unit is organized to include in each location of the unit's control store, to which control is not expected to transfer, a predetermined type of pattern containing an address specifying the address of that location, a suitable tag identifying the probable reason for the unexplained jump, and a transfer of control to the appropriate entry point in a reporting firmware routine within the control store. The reporting firmware routine has a number of entry points for collecting all the executions of unexpected locations and for storing the appropriate address and tag information in a predetermined register file for later referencing by an unusual event (UEV) handler routine.
摘要:
A memory translation mechanism and method executing in a second system to perform first system memory operations for first system executive and user tasks executing on the second system which includes a second system memory organized as a plurality of memory segments, wherein first memory segments are designated to correspond to system memory areas and second memory segments are designated to correspond to user memory areas, and wherein each memory segment corresponds to a combination of a type of first system task and a type of a first system memory area. An interpreter maps by reading an identification of the type of the task corresponding to the first system virtual address from the task type memory and the area type value from the first system virtual address and determining a memory segment corresponding to the type of the first system task and the type of first system area referenced by the first system virtual address. The interpreter maps the identified segment to a memory pool identifier wherein each memory pool identifier corresponds to a task. The second system includes a plurality of pseudo device drivers corresponding to first system input/output devices. Each pseudo device driver includes a segment mapping mechanism which includes a segment pool for storing entries relating memory pool identifiers and providing a corresponding base address identifying the location of the corresponding memory segment in the second system memory.
摘要:
Use of a control storage device coupled with a central processing unit is locked, during the loading process from the unit to the device, to a would-be user of the device until such loading process is complete as indicated by a so-called "unlock" command received from the central processing unit. An indication of an error or malfunction in the control storage device either during the loading process or thereafter is also provided to the central processing unit.