When browsing Google for an option to modify the Iomega ScreenPlay Pro HD I found a ScreenPlay Pro wiki and a Realtek RTD1261 wiki with lots of usefull information.

They both mention that you should be able to use telnet to connect to the ScreenPlay but that didn’t work with my version. The following steps describe how you can enable telnet if it doesn’t work. Use at your own risk!

First install the IFS driver to access the Ext2 Linux partition later. During the installation make sure you don’t check the option for read only access, we need to modify a file on the Ext2 partition. Now connect your ScreenPlay using USB and turn it on. In your control panel start the application “IFS Drives” and assign a drive letter to the Ext2 partition.

Browse to the drive and to “\etc” and open the “inetd.conf” file with for example Notepad++. Uncomment the line with telnet and save the file. Go back the “IFS Drives” in your control panel and remove the drive letter. Safely remove your USB drive from windows and start your ScreenPlay again. You will now be able to access it using telnet via the Network.