OS maps on Garmin Oregon 400/600

[Keeff]

I've been using a Garmin Oregon 400t, with OS maps, for about 4 years.

Thinking about upgrading to a 600, and have been wondering whether I need to buy a new set of maps or if the existing set will transfer.

At the moment, they are stored on the 400 machine, in a zipped file of about 2gb.  Am I correct in thinking that all I will need to do is use the back up copy I have on my PC and drop it either onto a SD card or into the new machine?

Will save about 100gbp if this is feasible.

In practice, I only really use the OS maps when we walk, preferring OSM for cycling.

Thanks for any advice you can give.

Keith

[Feanor]

Depend on how the maps were originally supplied.

If they were bought on an SD card, then they are locked to that SD card, and the SD card can be transferred to another device.
If they were bought on CD/DVD or download, they will be locked to the specific GPS device, and are not transferrable. Officially.

There are ways and means, of course...

[Keeff]

I seem to recall that I downloaded them from Garmin.

They are definitely in the machine rather than a card.

Keith

[Feanor]

The maps will be stored on the machine, in the \garmin folder, in a file called something like gmapsupp.img.
As you say, this will be about 2GB.

This file will be locked to your 400.

Officially, you will need to buy new maps for a new 600.
Simply copying the locked image onto a new device will likely give an error that the maps cannot be unlocked.

Un-officially, it is possible to un-lock the mapset using certain tools, so it will work on your new 600.
If you choose to go this way, PM me and I can help.