SHOWTIME 3.3 Update Notes:

The main changes between SHOWTIME 3.22 and 3.30 concern receiver specific
items:


MOTOROLA: After finally sorting out the GEOID sign situation, I got tired
of manually having to edit the *.GPS file to accommodate the different
corrections, so I added an automatic detection feature. During the
INIT@9600 phase, the receiver is queried to fetch the configuration.
It looks for a 5.x or 6.x receiver and sets GEOID=0, or GEOID=1 for a
7.0 thru 8.6 receiver release or GEOID=2 for receivers 8.7 and later
(which I still haven't seen). The user should no longer need to worry
about this problem! The GEOID switch has been removed from the [G]PS
mode screen. 

After the INIT@9600 message, the receiver info is displayed on the screen
briefly. If you want to get make note (like doing a screen print), hit
any key after you see the INIT@4800 message and the program will commit
suicide and stop after displaying the information.

The order of the lines in the *.GPS file format has changed slightly,
and several lines have been reformatted. An old file should work fine.

In doing all these changes, I stripped out the code that kept the
configuration checksum. After trying it, I decided it really wasn't
very useful.


GARMIN: SHOWTIME now supports the limited list of GARMIN receiver options.
You can manually select between 2D and automatic 3D operation. If you
plug in a non-ONCORE receiver, the software will automatically select
the proper APTYPE and GEOID switches.

The *.GPS file needed for the GARMIN is smaller than for the Motorola,
so when you do a [F]ile [U]pdate the un-needed information is stripped
out.

The timing sigma information now displays an estimate of the timing accuracy
even for the GARMIN. I haven't "calibrated" it well enough to develop
timing model parameters, and the software defaults to Motorola parameters.
You can change these in your *.GPS file in the MSIGMA line. An initial guess
would say that the GARMIN case is something like

   MSIGMA  500 500

i.e. an instrumental "noise" of about 500 nsec and sqrt(n) term of comparible
size (the cannonical Motorola vales are 10 and 100 nsec respectively).


BOTH: SHOWTIME has limited ability to automatically detect MOTOROLA vs.
GARMIN receivers, automatically setting the APTYPE parameter.

The detailed structure of the *.GPS files has changed, but old files should
work OK. After getting the receiver to run, it is recommended that you do
a [F]ile [U]pdate to re-write the new format *.GPS file. The *.GPS file
for the GARMIN has fewer entries since many parameters are not applicable.

Tom Clark