Browse Prior Art Database

Video Adapter for Multiple Touch Sensitive Displays

IP.com Disclosure Number: IPCOM000103864D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 4 page(s) / 97K

Publishing Venue

IBM

Related People

Harper, JD: AUTHOR [+5]

Abstract

Described is a video adapter hardware facility for multiple touch sensitive displays to enable multiple video and serial ports to be controlled with various combinations of display types and peripherals.

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

Video Adapter for Multiple Touch Sensitive Displays

      Described is a video adapter hardware facility for multiple
touch sensitive displays to enable multiple video and serial ports to
be controlled with various combinations of display types and
peripherals.

      The adapter facility is designed to function with personal
computer (PC) systems as used in point-of-sale applications.  It
provides the ability for the user to service up to four independent
video ports and the ability to drive liquid crystal display (LCD)
panels or color monitors from each video port.  Four serial ports are
provided for attachment of touch screen controllers or external
peripherals, such as serial printers and magnetic card readers.  Fig.
1 shows the circuit board configuration with four serial ports J5 to
J8 positioned at the edge of the board.

      The adapter facility contains a simple digital input port J14
which allows attachment of an external array of switches.  It has the
ability to control backlighting and contrast voltage of each LCD
panel independently and to sense the presence and type of monitor,
controller and LCD panel which may be attached.  It also has the
ability to select any one video port for read/write access.  One
video basic input/output system (BIOS) chip is shared by all four
video ports and one interrupt line is shared by all serial ports.

      Fig. 2 shows the video port selection circuit configuration.
Each of four video ports can display different information and can be
updated independently.  Registers available on the adapter provide
independent control of LCD panel backlight and contrast, monitor/LCD
sensing, and selection of active video ports for read/write access.
The video circuitry is implemented through separate piggy-back cards
to allow additional board space to be used and to allow for future
upgrading of the video capability.  Video port selection circuit with
a priority encoder to allow the selection of one and only one video
port for updating under software control.  There is also one circui...