Browse Prior Art Database

Flexible Multiple Touch Screen Interface

IP.com Disclosure Number: IPCOM000104304D
Original Publication Date: 1993-Apr-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 4 page(s) / 114K

Publishing Venue

IBM

Related People

Barrett, NP: AUTHOR [+3]

Abstract

Disclosed is a hardware and software design which overcomes the problems of providing a flexible interface for attaching multiple touch screens to a single system unit.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Flexible Multiple Touch Screen Interface

      Disclosed is a hardware and software design which overcomes the
problems of providing a flexible interface for attaching multiple
touch screens to a single system unit.

      Applications which require a large number of touch screens
running a similar program, ability to connect multiple touch screens
to a single system unit provides the most cost effective solution.
Several problems associated with a multiple touch interface are:
Speed of response; multiple touch screens must offer response times
which are not noticeably degraded compared to a single touch system,
Workable Interface;  control of multiple screens should be simple yet
offer the same advanced functions as single system, and Multiple
Operation;  the interface must provide a method of logically
organising the screens so that the system can determine from which
screen the touch data originated.

      The disclosed solution is a combination, shown in the figure,
of a PS/2* MICRO CHANNEL* adapter which electrically interfaces four
touch screens to the address and data busses of a PS/2 system unit,
and device driver software which controls the screens and provides
multiple touch screen functions to applications running on the
system.  Each of the touch screens has a controller chip on the
adapter which takes serial data from the touch screen and places it
on the data bus of the system.  These controller chips process
commands from the device driver to control the communication between
the system and the touch screen.  The adapter also contains address
decoding logic to allow each of the controller chips to be
individually addressed, and logic to meet the bus signalling
requirements of the microchannel architecture.

      The Device Driver supports two modes of operation, completely
individual touch screens where each screen reports the same
coordinates; the device driver can determine which screen originated
the data by reading the interrupt status of the controller chips on
the adapter.  For the second mode, each screen is configured to
report different ranges of touch coordinates, so that the system will
see a large logical touch screen, not individual touch screens.
Included in the solution are two Multiple VGA (MVGA) cards to drive
the video signals to the monitors.  The advantages are that speed of
response is comparable with that of a single touch screen because the
solution is interrupt driven.  Touch Screens require no changes to
controlling microcode and all touch functions are supported for each
of the multiple touch screens.  Also provided is a flexible multiple
touch interface to applications i.e.  independent or large logical
screen operation.

      The basis of an embodiment hardware is the 804...