Updating maps in garmin 19 and 21 year old dating
Click "View map updates for this product." This will tell you the latest version available for your device.
If it matches the version currently installed on your Street Pilot c340, you don't need to download a new map.
For example, the Via 135 doesnt, but the Via 135 M does (M stands for Maps).
This will enable you to download the updated map onto your device.
Contact Garmin customer support if you need assistance during this process.
You might want to buy additional maps – for example upgrading from UK & Ireland to full Western Europe – so you can use your satnav on holiday.
As long as your satnav is relatively modern (within the last five years or so), you should be able to update it.
Before I bought an i Phone, it had been a very useful tool for our travels.