Browse Prior Art Database

Dynamic Data Retrieval for Processor Simulation

IP.com Disclosure Number: IPCOM000102148D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Related People

Corrigan, MJ: AUTHOR [+2]

Abstract

A method is described which allows a computer processor simulator executing on a small machine, such as an IBM PC or PS/2*, to access random data from a very large amount of data stored on a larger machine, such as an IBM System/370* or IBM AS/400*. The data is accessed only as needed on a demand basis.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 75% of the total text.

Dynamic Data Retrieval for Processor Simulation

       A method is described which allows a computer processor
simulator executing on a small machine, such as an IBM PC or PS/2*,
to access random data from a very large amount of data stored on a
larger machine, such as an IBM System/370* or IBM AS/400*.  The data
is accessed only as needed on a demand basis.

      Within the PC or PS/2, a connection is made to a host computer
that contains a large database for use by a processor emulator.  This
connection may be by way of terminal emulation, or APPC connection or
any other connection that allows data to be passed between the host
computer and the microcomputer.  As the simulator processes
instructions and data by address, some addresses will not be known to
the simulator.  When these addresses are encountered, a call is made
to another program, or part of the same program to communicate with
the host computer.  The address is passed to the host, and the host
responds by fetching and returning the data associated with the
address. The data is stored in a very large database created from a
main storage dump of a failed system, or may even be actual live data
from a host system.

      Once the data is transferred to the PC or PS/2 environment, it
can be modified by simulated instructions without any impact or
change to the original source data residing on the host.  This is
desirable since changing the host data with untested code could
damage the host sys...