Browse Prior Art Database

Sensing the Presence of an Expansion Module

IP.com Disclosure Number: IPCOM000113984D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Strothmann, JA: AUTHOR

Abstract

Disclosed is a method for sensing the presence of an expansion module during the operation of a computer system. This method is particularly valuable in sensing a change to a computer configuration, which occurs if a module is installed or removed during the system operation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 90% of the total text.

Sensing the Presence of an Expansion Module

      Disclosed is a method for sensing the presence of an expansion
module during the operation of a computer system.  This method is
particularly valuable in sensing a change to a computer
configuration, which occurs if a module is installed or removed
during the system operation.

      The Figure shows an expansion module 10 having a connector 12
by which it is connected to a computer system 14.  Connector 12
includes a jumper 16 connecting a ground pin 18 with a presence sense
pin 20.  The connections through connector 12, between computer
system 14 and expansion module 10, include a ground line 22 connected
to ground pin 18 and a module presence sensing line 24 connected to
presence sense pin 20 and a number of connections to other signal and
voltage lines 25.  Presence sensing line 24 is also connected to a
voltage VCC through a resistor 26.

      Thus, when expansion module 10 is present, connected to
computer system 14, sensing line 24 is held at a ground potential
through jumper 16.  On the other hand, when module 10 is removed,
sensing line 24 is pulled up to the voltage VCC through resistor 26.
The potential level of sensing line 24 is monitored by a processor,
controller, or other logic, so that the system is signalled whenever
a configuration change occurs during system operation due to the
removal or installation of a module 10.

      Without this feature, since configuration data is provided...