	     Some Frequently Asked Questions about LXGPS

Q. I can't get LXGPS to talk to my GPS.  What do I do?

A. First make sure that your serial port is enabled.  In the built-in
   Setup app, make sure 'Enable Com1 Port in DOS' is checked.  Also,
   you may have to use the d:\bin\serctl /w command at the DOS prompt.
   If you're using BUDDY, make sure it turns on the serial port (++
   from FILER).

   See if you can get output from your GPS using the built-in DataComm
   application.

   Check your cables.  If you're using the 100/200LX's serial
   cable to connect to the GPS's serial cable you probably need a null
   modem adapter (not just a gender changer).

   If you launch LXGPS from the App Manager, make sure you've got an
   upside-down exclamation point in the comments field (Fn FILER) to
   ensure the serial port isn't getting messed up by the System
   Manager.

Q. Where do I get maps for LXGPS?

A. I've been using screen captures from Delorme's Street Atlas (which
   came with the Tripmate GPS).  For the US map that comes with LXGPS,
   I used the Xeroc PARC map viewer (http://mapweb.parc.xerox.com/map).
   There are several other sources of maps on the Web.  Here are a
   few:

	www.mapblast.com
	tiger.census.gov
	www.delorme.com

   To use a map with LXGPS it must be in 1 bit-per-pixel PCX format.
   Before LXGPS can use it, you must calibrate it.  To calibrate a
   map, you need to know the latitude and longitude of two points on
   the map.  Also the map must be oriented with North up, West left
   and the horizontal and vertical axes must be linear.

Q. How can I convert maps to 1 bit-per-pixel?

A. Most image editing/paint programs will allow you to convert an
   image to 1 bit-per-pixel.  I've had good luck with Paint Shop Pro.
   Your local web archive should have a good selection of programs.
   Try www.download.com for a start.  If you want to do the conversion
   on the palmtop, try LXPIC (http://home.t-online.de/home/stefan.peichl/).

Q. Does LXGPS support the Delorme Earthmate?

A. Not at this time.  The Earthmate uses a binary protocol rather than
   the standard NMEA 0183 protocol.

Q. Can I use LXGPS on my desktop or laptop?

A. Yes.  But since LXGPS uses HPLX specific graphics functions you need a
   helper program to emulate them.  I use CGAGRAPH.COM which is available
   with the PAL distribution from:

	http://ourworld.compuserve.com/homepages/gilles/pal/pal.htm

   Use ALT-F10 to access the LXGPS menu items.

Q. What's the largest size map I can use with LXGPS?

A. The PCX format uses signed shorts for the dimensions so that limits you
   to 32767 x 32767 pixels.  LXGPS only reads in a single line of the map
   at a time so there shouldn't be much of a memory constraint.  One thing
   to keep in mind is that LXGPS has to read in (and decompress) each line
   up to and including the portion that's displayed.  For wide maps that
   can result in slower scrolling the further to the right you are on the
   map.  The .IND file takes care of this problem for the vertical
   dimension, however.

   With all that said, I've only ever used maps of about 1280 x 1024.
   With the automatic map switching I haven't seen a need to use larger
   maps.

Q. I'm having problems converting and calibrating maps?

A. Beverly Howard provided this tutorial:

   LXGPS Map Conversion and Calibration notes.

   The following is a sample run using Delorme Street Atlas and IrFanView 
   to prepare maps for LXGPS.  
	
   The image editor referenced below is IrFanView...  a _freeware_ image
   manipulator available at http://www.irfanview.com

   While I have accomplished the image processing with a variety of image
   programs, the above software is universally available, free, easy and
   has all of the tools necessary to complete the conversion from a
   Delorme color clip to a 1 bit pcx file.

   ======Windows Setup=============

   Set Windows Desktop to maximum pixel resolution

   For larger images, use "Virtual Desktop" if available (you may have to
   reduce colors)

   =======Delorme Street Atlas======

   Maximize Street Atlas

   Turn off all toolbars and status bar

   Size and position map (Scroll to confirm if using "Virtual Desktop")

   Select "Copy Map to Clipboard"

   Paste into image editor (IrFanView)

   Return to Delorme (Note avoid "Right Clicking" in Delorme as this will
   reposition center of map)

   Pick and note the names two landmark "diamond" marks near opposite
   corners of image

   Zoom in to _maximum_ resolution on each of the landmark diamonds you
   picked

   Right Click on landmark and select "Lat/Long on Map Note"

   Right Click resulting "Note"

   Select Properties

   Copy Lat/Long and paste into text file for future reference

   Repeat for second diamond

   (Note...  for maps displayed by other applications that do not have a
   copy option, press the <PrtScreen> key to copy the current screen to
   the clipboard)

   =======IrfranView=============

   Paste image

   Select "Greyscale"

   Select "Sharpen" several times (to your taste)

   Select Image/DecreaseColorDepth

   Select 2 color

   Save as PCX file

   ========LXGPS=================

   Specify PCX Map in Settings/Files/Map

   LXGPS will automatically go to "Calibrate" mode with "crosshairs" at
   upper left of map

   Delorme "diamonds" should fit exactly in map "cross hairs"

   Cursor moves 10 pixels per cursor arrow press...  use <Shift-Arrow> for 
   1 pixel movement.  (If running on non LX machine, numeric pad must be 
   used instead of cursor pad for 1 pixel movements.) 

   Select "point-1" and enter lat/long in following format

	N 30 58.946
	W 98 42.444

   Repeat using the diamond near the opposite corner for "point-2"

   Select "Calibrate"

   Select Invert for LCD displays

   Select Save

   Select Done

   Repeat for each map

$Id: faq,v 1.9 2001/07/18 23:10:50 greg Exp $

