Browse Prior Art Database

ID-Bit Architecture for Displays

IP.com Disclosure Number: IPCOM000112982D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27

Publishing Venue

IBM

Related People

Knox, A: AUTHOR

Abstract

Disclosed is a method of extending an existing monitor ID scheme while providing power-off monitor ID for use with an active system, plus a Communication channel via the ID bits. The need is solved for more monitor IDs which can now also be read with power on/off together with support for new/additional monitor function on existing installed interfaces. Included is a scheme of microprogram control of monitor ID-bits.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 42% of the total text.

ID-Bit Architecture for Displays

      Disclosed is a method of extending an existing monitor ID
scheme while providing power-off monitor ID for use with an active
system, plus a Communication channel via the ID bits.  The need is
solved for more monitor IDs which can now also be read with power
on/off together with support for new/additional monitor function on
existing installed interfaces.  Included is a scheme of microprogram
control of monitor ID-bits.

      The current ID bit scheme used to communicate the display type
attached to the system unit is now inadequate to support the function
required.  If the unallocated ID of '1111' is used with links and
diodes between pins on the display side then in an adaptor which has
read and write ability in its ID lines the scheme may be extended to
overcome these difficulties whilst remaining compatible with all
current displays and systems.  Extensions may also be realized to
provide an effective communication interface between the display and
the system to which it is attached by use of the ID bits.  At
present, after boot up of the system these links between the system
and display are redundant.

      Proposed is that unallocated ID bits of '1111' be used as the
basis for this scheme.  This _ has useful properties, one of which is
that none of the ID pins are connected to ground which presents an
immediate problem to adaptors that look at ID bits because these will
be unrecognized.  As this scheme is intended for use with advanced
displays, equipped with microprocessors, adding to their current
functions the ability to control the display ID bits is a simple
task.  The presentation of a valid ID when the display is turned off
is also easily rectified.

      Communication between display and system is a key requirement
in the evolution of the total system.  Once this is present, major
advances can be made in various fields relating to computing
equipment such as Cable management.  The trend toward multimedia
systems has added to the present keyboard and mouse cables in
addition to the display interface cable.  Effective communication
will also enable a host of advanced display functions that are
currently unable to be implemented.  It is inappropriate that
individual displays have a unique ID.  Conversely, all displays
shouldn't have the same ID, an unfortunate condition that prevails
with multisynchs at present.  Display IDs should be selected
according to their abilities or "attributes".

      With this new scheme called ID 15, compatibility is the
overriding objective whilst also providing an expansion path to the
old display ID concept which has reached a dead end in its present
form.  Compatibility issues have been successfully overcome with the
ID 15 scheme but the enhanced function requires additional hardware
to be present both in the system and display.  For basic
implementations of ID 15, this additional hardware is minimal.
Displays are a cost...