Sand Man (SA) replied:

john,

Why do you want to change to Aus 66.

I use Discover Aus on a Magellan Platinum and have the datum set for WGS84.

You need to match the datum setting on the GPS to match the Maps you are using to get the best accuracy.

Charlie replied:

Change it on the GPS if your using a paper map with AUS66,up and download is automaticly converted to the us datum anyway.
Regards Charlie

The Explorer replied:

Hello - the readout in DiscoverAus is always WGS84 - you cant change it . Changing the datum on the GPS is achieved through the setup menu (ie press menu and then setup and there will be an option to change datums). With repsect to readout and waypoints this only changes the datum in which the data is displayed..it is still stored on GPS in WGS84.

If you are using moving map (GPS log)...depending on model of GPS, changing the display datum on gps from WGS84 may make DiscoverAus plot your position incorrectly ...as it is expecting NMEA data in WGS84 and there is no way of telling it otherwise (ie changing dispaly datum will change the datum of NMEA data).
Cheers
Greg

awill4x4 replied:

I would assume that if you have downloaded some waypoints to your GPSr that you have logged from your computer DiscoverAus program and then change to Aus 66 in your GPSr that the waypoints would then change to Aus 66 coords.
Regards Andrew.

john replied:

I do not have the computer in the car. When I down load the computer setting doesn't change to the same as the GPS. All the maps I have are in Aus66.

Still I can't work out how to change on the computer the datum???