公开(公告)号：IT1163717B

公开(公告)日：1987-04-08

申请号：IT2608179

申请日：1979-09-28

Applicant: IBM

Inventor： MITCHELL GLEN ROBERT ,  SOLTIS FRANK GERALD ,  HOFFMAN ROY LOUIS

IPC: G06F9/34 ,  G06F9/355 ,  G06F12/02 ,  G06F12/06 ,  G06F12/10 ,  G06F

Abstract: Virtual addressing apparatus for implementing a large virtual address in a computer system having narrow data paths, ALU, and local storage register arrays without requiring multiple passes. The virtual addressing apparatus stores the segment portion of a virtual address in a segment register and the offset portion of the virtual address in an offset register. To form a new virtual address, a new offset value is obtained by adding the displacement value given by the instruction in the instruction buffer register to the offset value stored in the offset register. The segment portion of the virtual address does not participate in the arithmetic operation for forming the new virtual address. The segment and offset portions are concatenated to form the new virtual address which is then translated to a main store address. Overflow detection circuitry in the ALU detects if an overflow out of the offset occurs as a result of the ALU operation for obtaining the new offset value. If an overflow is detected during the calculation of the new offset value, translation of the virtual address is subsequently aborted.

公开(公告)号：IT1162587B

公开(公告)日：1987-04-01

申请号：IT2607979

申请日：1979-09-28

Applicant: IBM

Inventor： COLLINS ROBERT WILLIAM ,  HOFFMAN ROY LOUIS ,  LOEN LARRY WAYNE ,  MITCHELL GLEN ROBERT ,  SOLTIS FRANK GERALD

IPC: G06F12/10 ,  G06F12/12 ,  G06F

公开(公告)号：DE3069585D1

公开(公告)日：1984-12-13

申请号：DE3069585

申请日：1980-06-03

Applicant: IBM

Inventor： HOFFMAN ROY LOUIS ,  KEMPKE WILLIAM GEORGE ,  MCCULLOUGH JOHN WARREN ,  SOLTIS FRANK GERALD ,  TURNER RICHARD TAD

IPC: G06F9/46 ,  G06F9/48 ,  G06F3/04

Abstract: The specification concerns a task handling apparatus for a computer system where the task dispatcher is selectively operable under instruction control for performing task queue selection and where the intertask communication mechanism can return a task dispatching element (TDE) to a non-prime task dispatching queue (TDQ) as well as to the prime TDQ. Whenever a TDE is returned to the prime TDQ, the task dispatcher makes a pre-emptive task switch. Also, if there are no task dispatching elements on the current non-prime TDQ, the task dispatcher switches to dispatch TDE's from the prime TDQ.

公开(公告)号：AU3645078A

公开(公告)日：1979-11-29

申请号：AU3645078

申请日：1978-05-24

Applicant: IBM

Inventor： HOFFMAN ROY LOUIS ,  SOLTIS FRANK GERALD ,  TURNER RICHARD TAD ,  KEMPKE WILLIAM GEORGE ,  MCCULLOUGH JOHN WARREN

IPC: G06F9/46 ,  G06F9/48 ,  G06F9/18

Abstract: Task handling apparatus in a computer system is structured to be common to system control tasks, user tasks and I/O tasks. Although the task handling apparatus contains a task priority structure, all tasks are handled in the same manner, and there are no fixed interrupt levels for I/O tasks. There are N levels of priority, and N is variable. Each task is a server for a functional request. Task dispatching elements (TDE's) are enqueued in priority sequence on a task dispatching queue (TDQ). A task dispatcher functions to dispatch the highest priority TDE on the TDQ, if any, and to perform task switching. Intertask communication is accomplished by send message, send count, receive message and receive count mechanisms, and is coupled with task synchronization. Task synchronization is achieved by dequeueing and enqueueing TDE's on the TDQ. An active task becomes inactive dispatchable when a higher priority TDE is enqueued on the TDQ by send message or send count mechanisms. The active task becomes inactive waiting when a receive message or receive count is not satisfied. An inactive dispatchable task becomes the active task when it becomes the highest priority enqueued TDE on the TDQ by the receive message or receive count mechanisms. An inactive waiting task becomes either the active task or an inactive dispatchable task after being enqueued on the TDQ by the send message or send count mechanisms, depending upon whether it is the highest or other than the highest priority TDE on the TDQ.

公开(公告)号：DE2828544A1

公开(公告)日：1979-01-25

申请号：DE2828544

申请日：1978-06-29

Applicant: IBM

Inventor： HOFFMAN ROY LOUIS ,  KEMPKE WILLIAM GEORGE ,  MCCULLOUGH JOHN WARREN ,  SOLTIS FRANK GERALD ,  TURNER RICHARD TAD

IPC: G06F9/46 ,  G06F9/48 ,  G06F9/18 ,  G06F3/04

Abstract: Task handling apparatus in a computer system is structured to be common to system control tasks, user tasks and I/O tasks. Although the task handling apparatus contains a task priority structure, all tasks are handled in the same manner, and there are no fixed interrupt levels for I/O tasks. There are N levels of priority, and N is variable. Each task is a server for a functional request. Task dispatching elements (TDE's) are enqueued in priority sequence on a task dispatching queue (TDQ). A task dispatcher functions to dispatch the highest priority TDE on the TDQ, if any, and to perform task switching. Intertask communication is accomplished by send message, send count, receive message and receive count mechanisms, and is coupled with task synchronization. Task synchronization is achieved by dequeueing and enqueueing TDE's on the TDQ. An active task becomes inactive dispatchable when a higher priority TDE is enqueued on the TDQ by send message or send count mechanisms. The active task becomes inactive waiting when a receive message or receive count is not satisfied. An inactive dispatchable task becomes the active task when it becomes the highest priority enqueued TDE on the TDQ by the receive message or receive count mechanisms. An inactive waiting task becomes either the active task or an inactive dispatchable task after being enqueued on the TDQ by the send message or send count mechanisms, depending upon whether it is the highest or other than the highest priority TDE on the TDQ.