Article Title	 	: tablet support
Creation Date		: 06/15/94
Message ID		: SGLNGQ
Last Update		: 
Expiration Rules	: unknown
Location		: techtips/Archive/NCD-Articles/peripherals
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Tablets are supported by applications, and different applications use different
methods to support them.  NCD gives applications three basic ways to access
tablets that you have attached to the serial port on the NCD.

1. X Input Extension.  Note that this support is included only in the PEX
server, not the standard NCDware server, but a PEX license is *not* needed to
use the Input extension. 

For an application so support a tablet through the X Input Extension, it does
not need to know what kind of tablet is attached, as long as the X server in
the terminal can support the tablet. We support Summagraphics protocol, which
most tablet manufacturers support.  Many applications are moving to this type
of support, as it simplifies life for the software vendors.


2. TCPCON.  NCD provides this public domain program to allow programs to
control directly a device attached to the NCD serial port.  TCPCON runs on the
host where the application runs, creating a pseudo tty to which the application
connects. The source code is on the contrib CD.

The application has more of a burden to support tablets this way. Each tablet
must be supported by a device driver within the application. In this case, the
list of supported tablets is dictated not by NCD, but by the application. The
only restriction imposed by NCD is that the tablet must be able to connect to
the NCD serial port.


3. Some applications use the X core pointer (the mouse cursor), and expect that
it is driven by an absolute device like a tablet.  In the 3.2.1 PEX server, NCD
allows you to select the pointing device (mouse, input extension device, or
both).  Using the tablet as the pointing device will satisfy applications who
use a tablet by assuming that it is controlling the core pointer device.