公开(公告)号：CA1024658A

公开(公告)日：1978-01-17

申请号：CA215258

申请日：1974-12-02

Applicant: IBM

Inventor： LEWIS DAVID O ,  MILLER THOMAS H ,  SCHMITT STEVEN A

IPC: G06F3/00 ,  G06F13/10

Abstract: A computer system executes instructions for an I/O device not attached to the system. A quasi I/O attachment device is responsive to the commands for the unattached I/O device and generates an interrupt condition. The interrupt condition causes the command instructions for the unattached I/O device to be translated to command instructions for an I/O device connected to the computer system. The I/O device attached to the system performs the designated operation and generates associated I/O device status data. This associated I/O device status data is translated into I/O device status data for the unattached I/O device and thus permits a program for operating an unattached I/O device to operate instead an I/O device attached to the system which otherwise could not be operated by that program. A second embodiment performs the emulation of the unattached I/O device remotely of the central processing unit in the computer system.

公开(公告)号：FR2279159A1

公开(公告)日：1976-02-13

申请号：FR7441650

申请日：1974-11-15

Applicant: IBM

Inventor： LEWIS DAVID O ,  MILLER THOMAS H ,  SCHMITT STEVEN A

IPC: G06F3/00 ,  G06F13/10 ,  G06F13/00

Abstract: A computer system executes instructions for an I/O device not attached to the system. A quasi I/O attachment device is responsive to the commands for the unattached I/O device and generates an interrupt condition. The interrupt condition causes the command instructions for the unattached I/O device to be translated to command instructions for an I/O device connected to the computer system. The I/O device attached to the system performs the designated operation and generates associated I/O device status data. This associated I/O device status data is translated into I/O device status data for the unattached I/O device and thus permits a program for operating an unattached I/O device to operate instead an I/O device attached to the system which otherwise could not be operated by that program. A second embodiment performs the emulation of the unattached I/O device remotely of the central processing unit in the computer system.

公开(公告)号：CA1050169A

公开(公告)日：1979-03-06

申请号：CA300238

申请日：1978-03-31

Applicant: IBM

Inventor： LEWIS DAVID O ,  MILLER THOMAS H

IPC: G06F13/04

Abstract: SCAN AND READ CONTROL APPARATUS FOR A DISK STORAGE DRIVE IN A COMPUTER SYSTEM Control apparatus is provided for controlling a disk storage drive attachment in a computer system whereby records stored on the disk storage media are scanned and read within the same data field. The search key or search argument contained in main storage of the computer system is retrieved and compared with the key in the disk data field being scanned. The storage locations in the scan field not containing the search key are set to hexidecimal FF. The central processing unit (CPU) of the computer system is in a write to disk storage drive mode whereby the search argument is transferred from storage to the disk storage drive attachment as data is read from the disk storage drive. Decode apparatus senses the first hexidecimal FF from storage and switches the operation from a scan mode into a read mode and if a scan low or equal condition resulted from the comparison, the disk data field is read into the storage scan field with one byte of FF between the search key in storage and the newly stored disk data. The one byte of FF still provides an indication of the end of the search key. The operation then switches back to the scan mode and repeats in the manner described, i.e., sequential disk data fields are read into the storage scan field, until a comparison of equal or high results. When a high condition exists, a latch is set to block the storage of disk data in main storage because the storage scan field now contains the disk data field which had been sought, i.e., the one containing the desired index key.

公开(公告)号：CA1038500A

公开(公告)日：1978-09-12

申请号：CA209551

申请日：1974-09-19

Applicant: IBM

Inventor： LEWIS DAVID O ,  MILLER THOMAS H

IPC: G06F3/06 ,  G06F13/04

Abstract: SCAN AND READ CONTROL APPARATUS FOR A DISK STORAGE DRIVE IN A COMPUTER SYSTEM Control apparatus is provided for controlling a disk storage drive attachment in a computer system whereby records stored on the disk storage media are scanned and read within the same data field. The search key or search argument contained in main storage of the computer system is retrieved and compared with the key in the disk data field being scanned. The storage locations in the scan field not containing the search key are set to hexidecimal FF. The central processing unit (CPU) of the computer system is in a write to disk storage drive mode whereby the search argument is transferred from storage to the disk storage drive attachment as data is read from the disk storage drive. Decode apparatus senses the first hexidecimal FF from storage and switches the operation from a scan mode into a read mode and if a scan low or equal condition resulted from the comparison, the disk data field is read into the storage scan field with one byte of FF between the search key in storage and the newly stored disk data. The one byte of FF still provides an indication of the end of the search key. The operation then switches back to the scan mode and repeats in the manner described, i.e., sequential disk data fields are read into the storage scan field, until a comparison of equal or high results. When a high condition exists, a latch is set to block the storage of disk data in main storage because the storage scan field now contains the disk data field which had been sought, i.e., the one containing the desired index key.