Browse Prior Art Database

Bus Connection / Disconnection by Software

IP.com Disclosure Number: IPCOM000117602D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Kondoh, M: AUTHOR

Abstract

Disclosed is a method for connecting and disconnecting a bus that interconnects between two computer systems. It should be noted that the subject method can be embodied by a software program.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 84% of the total text.

Bus Connection / Disconnection by Software

      Disclosed is a method for connecting and disconnecting a bus
that interconnects between two computer systems.  It should be noted
that the subject method can be embodied by a software program.

To implement this invention, the two computers are assumed to have
the following properties:
  o  A system X can electrically separate its own memory based on a
      signal from the other system Y, so that the other system Y can
      have exclusive access to the memory.
  o  The system Y can send the above signal to the system X when a
      physical connection is established.

      As a sample application of this mechanism, assume that the
system X is a Personal Computer (PC) Card, the system Y a PC system,
and you want to transfer the time of day information from the PC to
the PC Card.  The signal used is the PC Card's power (Vcc) line.
  1.  The PC Card is inserted in the PC so that the two computers are
       connected physically, allowing the PC to supply power to the
PC
       Card.
  2.  A program in the PC Card detects the presence of power supply
       from the PC, and separates its own memory from its bus.
  3.  Another program in the PC detects the presence of the PC Card,
       maps the PC Card's hardware resources including memory to its
own
       bus, writes the time of day information into the PC Card's
       memory, then releases all the hardw...