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good precision,  and very low cost. The system consists of stepper
motors added to the altitude and azimuth axes,  and driven by the PC.
All of the "intelligence" for alignment,  etc. is in the Alt/Az
software,  making for very minimal hardware requirements.

   If you have an interest in connecting your own, customized
computer-controlled telescope to Guide,  you may wish to check the
file \COMPRESS\XTROL.DOC on the CD-ROM. It contains some
data on how communication with LX-200 and ALTAZ systems is done
by Guide.

11a:  Encoder-based systems         

   As was mentioned above,  handling alignment of JMI/MG-III type
systems ("Tangent Instrument boxes") is a somewhat different process
from that required for other systems.  The other systems have built-in
hardware to handle alignment.  Tangent Instrument boxes require Guide
to handle that task.

   To use your JMI/MG-III compatible encoders,  hook up the interface
to the computer,  start Guide,  and click on "Settings... Telescope
Control".  Select the serial port used for the encoders;  this is
usually COM2,  but it may be COM1 on some laptops.  And in some odd
cases, it may be COM3 or COM4.

   Also,  select the "JMI/MG III" radio button,  and enter the scope
resolution in the boxes at the bottom of the dialog.  Click OK.  After
a short pause,  Guide will provide a "Scope resolution successfully
set" message,  and will add the "Scope Pad" option to the menu bar.
(If it shows any other message,  then Guide has been unable to set the
encoder resolution correctly.  Check the encoder connections and make
sure the COM port has been set up correctly.)

   If Guide succeeds in communicating with the scope,  it will move
to the next step.  You'll see a small dialog box,  asking if you have
an "equatorial reading hour angle",  an alt/az,  an alt/az scope on
an equatorial platform,  or an equatorial reading RA.  The alt/az
options are straightforward enough, but the equatorial options
require some explanation.  It seems that encoders on equatorial
scopes are about evenly divided between two mounting methods. Some
people use one encoder to measure the hour angle at which a telescope
is pointed;  with the drive motor on,  this encoder reads a changing
value as the scope moves. Other people, though, will use one encoder
to measure the RA at which the telescope is pointed.  In such a case,
the drive motor doesn't force the encoder to move.

   Unfortunately,  Guide has no way to determine which system you're
using. So when you add the first alignment star,  it will ask you for
this information.

   Click on the "Scope Pad" option,  and you'll get a small dialog box

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