Before messing with the timekeeper chip or exchanging the battery it is very important to backup game saves you don’t want to lose from the NVRAM. With a null-modem cable hooked up to a PC there are two options to communicate with the CD-i player:
To build a cable we need a standard serial extension cable and a male 8-pin Mini-DIN connector. Remove the male D-Sub connector and keep it for later (we need it for the Atari Jaguar mouse adapter).
In the CD-i Link archive are instructions on how to build a null-modem cable with three wires. Unfortunately it didn’t work with my setup and I had to rebuild it later with six wires according to the original specifications.
This is the CD-i’nterlink disc menu (it’s also called CD-interlink or CD-Interlink within the program). With it you can list, view and delete files in the NVRAM. When connected to a PC you can send/receive them via the X- and Z-Modem protocols or start the host mode (mouse cursor):
The host mode allows a PC terminal program to manipulate the NVRAM files. This is how it looks like in Windows Hyper Terminal: