To check the firmware version on your Olympus DS-3400 digital voice recorder, follow the steps below:
1. Turn the recorder ON
2. Access the MENU by pressing and holding the MENU button for a second.
3. Scroll down to select Device Menu, then press OK
4. Scroll down to select System Information, then press OK
4. Scroll down to view the firmware version number.
As of 1.6.11, the latest firmware version is 1.01
Verification Source: In-house testing