puff(1X)																  puff(1X)

NAME

       puff - An X program for sight-impaired users

SYNOPSIS

       puff [-toolkit_option] [-option]

OPTIONS

       Have  Puff's  false server listen at a different display number.  By default, Puff listens to display number 1.	Set the magnification fac-
       tor.  The magnification is constrained to be an integer greater than zero.  The default is 6.  Specify in milliseconds how often to  update
       the  Puff  window  in  the absence of pointer of graphics activity.  For example, to update every second, use a value of 1000.  The default
       update rate is 500 milliseconds, or 2 Hz.  An update value of zero turns off periodic updating.	Specify the size  of  the  pointer  cursor
       block  in the Puff window. The actual dimension of the block is '2 * cursorWidth * magnification'. The default cursor width is 3. The width
       of the view box outline is `cursorWidth + magnification'.  Display a short command summary.

DESCRIPTION

       Puff (puff) is intended for people who need text and graphics displayed at a high magnification factor.	Typically users will want both the
       pointer and text to be tracked as they work.

       Puff  follows  the  pointer (also known as the mouse), magnifying a part of the screen under the cursor.  In addition, Puff can monitor the
       X11 protocol of X clients and magnify the region where graphics were last drawn.  By monitoring a program like xterm, Puff can  follow  the
       text cursor automatically.  Puff switches focus between the pointer and graphics, depending on which was last active.

       In  order  to  track  the  protocol  of	X  clients, Puff sets up a false server on the machine that it is executed on.	This server is, by
       default, at display number 1.  Any X clients connecting with this false server are connected to the same X server that  Puff  is  connected
       to.  Puff is transparent to X clients.

       Puff  draws  a box around the location being magnified, which makes it easier to track the cursor and see where Puff is focusing its atten-
       tion.  The view box flashes on each update.

INTERFACE

       Puff is controlled via the keyboard.  The following keys have these actions: Change the magnification factor  to  2-18,	20,  25,  and  30,
       respectively.  Toggle showing the view box.  Quit Puff.	This will also finish off any clients running through Puff.

       The following arrow key commands make it easier to scan text and graphics: Move the magnification window up by 1/4 the window height.  Move
       the magnification window down by 1/4 the window height.	Move the magnification window right by 1/4 the window width.  Move the	magnifica-
       tion window left by 1/4 the window width.  Return to the point of interest.

ADDITIONAL RESOURCES

       The  following  resources  apply  to the Puff widget, of class puff: Set the magnification factor in the horizontal direction. The resource
       value must be a positive integer.  Set the magnification factor in the vertical direction.  The resource value must be a positive  integer.
       Graphics  and  pointer  activity  are  accumulated  for	delayMin  milliseconds before Puff updates to avoid overwhelming the X server.	To
       decrease Puff's impact, increase delayMin.  The default value is 50 milliseconds, or 20 Hz.  If the viewBox resource is nonzero,  the  view
       box will be drawn.

EXAMPLES

       In practice, Puff is used on the top half of the screen, with clients running on the bottom half.  A sample file might read:

       #!/bin/csh xrdb -load $HOME/.Xdefaults xclock -geometry -10-10 & puff -geometry 1280x500+0+0 & xterm -display :1 -geometry 80x32+5-5 & twm

       For an example of how Puff follows the display, enter the following command after starting Puff:

       xclock -display :1 -u 1

CAVEATS

       If  run over a network, Puff can consume a good portion of an Ethernet's bandwidth.  To be a good citizen, run Puff on the same workstation
       as the X server whenever possible.

       If available, Puff will use the MIT Shared Memory X server extension, which greatly improves  performance.   However,  if  terminated  with
       extreme	prejudice  (that  is,  kill -9), the program will not have a chance to release the shared memory segments it was using.  The ipcrm
       program can be used to free up Puff's mess.

       Puff will grab all Ctrl arrow-key events, depriving other clients.  This obnoxious behavior should be made an option.

AUTHOR

       AHPCRC (Army High Performance Computing Research Center)

SEE ALSO

       X(1X)

																	  puff(1X)