I contacted the Adinstrumens support about the subject, and they gave me the information that the I²C port of the Adinstruments channel recorders can only be used to connect front-ends. It cannot be used to read out data.
The Adinstruments support gave me the information, that Adinstruments never sells channel recorders without software. With the serial number and the ebay seller, it was possible to find out, that the channel recorder was from a company who went out of business some time ago.
Adinstruments gave me a replacement copy of their Chart software. The 4100 needs a SCSI card, and they gave me a Chart software is windows xp compatible. It could be installed in Windows 10 in the XP compatibilty mode.
I had problems that the fuses broke when connected the channel recorder to a power source. My hypothesis was, that the device was damaged. But the Adinstruments support gave me the information, a device to adapt the voltage from 110 V to 220 V is needed. Only the newer devices work without such an adapter.
I bought a second channel recorder from Adinstruments on ebay, a 8 SP with usb interface. Also this device was sold without software. The Adinstruments support gave me the information, I could use the same Chart software with it they gave me for the first recorder.
The 8 SP has only BNC connectors. I have Adinstruments ECG sensors and respiration sensors. They cannot be plugged in in the 8 SP. For the respiration sensor, an adapter is needed, and for the ECG sensor, an aditional Bioamp front end is needed.
The chart software is very basic. As far as I have seen, it can only be used to aquire data. But these data can be analysed with 3. party software. Adinstruments has their Labchart software. I saw it only once a year on ebay for around 350 USD. To use the 8 SP with Matlab, the Labchart software is needed.
I probably will use the Adinstruments channel recorders only as reference devices. There are other options available with more options than this basic Adinstruments equipement, which cost less, like the Bitalino low-cost medical toolkit, or simply by connecting biosensors though a soundcard to a PC:
https://www.eevblog.com/forum/testgear/light-weight-usb-oscilloscope-with-matlab-support/A full Adinstruments equipement with more options would cost I guess around 2000 USD. This is only an estimation from prices on ebay. Adinstruments does not publish any prices.