Browse Prior Art Database

Host System and Attached Non-Programmable Terminal with Open Parallel Port

IP.com Disclosure Number: IPCOM000116506D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 214K

Publishing Venue

IBM

Related People

Aaker, KD: AUTHOR [+8]

Abstract

A method for providing a host system with an application programming interface (API) for an open parallel port and an attached non-programmable terminal (NPT) which has an open parallel port are disclosed. Image scanner extensions are also described.

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Host System and Attached Non-Programmable Terminal with

Open

Parallel

Port

      A method for providing a host system with an application
programming interface (API) for an open parallel port and an attached
non-programmable terminal (NPT) which has an open parallel port are
disclosed.  Image scanner extensions are also described.

      Some Non-Programmable Terminals (NPTs) have a parallel port.
Some NPTs have the ability to display image and facsimile.

      In order to support an open parallel port on an attached NPT,
the host system could support a new Application Programming Interface
(API), the display data stream could be enhanced, work station
controllers (WSCs) and NPTs could be enhanced.

      The display data stream architecture could be enhanced in the
following ways:
  o  A new Write Non-Screen Data command could be defined.  This
      command could have a Write Structured Field format: Major
Length,
      Class, Type (indicates this specific command), Major Flags,
      followed by one or more minor structures.  Each minor structure
      could have the following format: Minor Length, Minor Type, and
      Optional Data.  Each minor structure could do something
      non-screen related.  For an open parallel port, a specific
Major
      Flag indicates this command is targeted to an open parallel
port.
      For an open parallel port, typical Minor Types may be: Write
data
      out the open parallel port using a specific parallel port
      protocol and Read data from the open parallel port using a
      specific parallel port protocol.
  o  A new Read From Open Parallel Port command is defined.  This
      command allows data to be received into the host from the open
      parallel port.  The format of the resulting read data could
      include length of the data, a flag byte which indicates if this
      is the last of the read data, followed by open parallel port
data.
  o  A new AID value could be defined to pass back error information
      from an open parallel port (AIDs normally define a specific
key;
      for example, Enter or Help).  If the user cancels a parallel
port
      operation or an open parallel port error occurs, the host could
      receive error information.

      An image scanning API could be added on the host system.  The
function of the new image scanning API could be described by the
following sequence:
  o  A host application could offer a menu where the user initiates
      image scanning.  The user may pick things like image resolution
      (for example, low resolution preview or normal resolution) and
      scanning dimensions.
  o  When the user requests an image scan, the host application could
      fill in a data structure with the following: where to store the
      image on the host system, maximum size of the image data,
sca...