So I pimped my CDTV! A few months ago I was able to get a replacement CD-drive, because the old one only worked sometimes and most of the time it did not work at all.
And now I put in a 2MB RAM expansion, a SCSI-adapter and a SCSI to SD card reader that works as a harddisk.
Besides these wonderful expansions I installed a joystick adapter. As you may know the CDTV is used with a remote controller. This controller is not very suitable for playing games. So I bought a joystick adapter from eBay.
The only thing I need to do is make a nice slot to install both joystick connectors into.
The four components (RAM expansion, SCSI adapter, SCSI2SD and joystick adapter):
Picture from http://www.a1k.org/forum/showpost.php?p=492091&postcount=566.
Picture from http://imall.iteadstudio.com/scsi2sd.html.
Pictures from the eBay auction of seller '24mata'.
A big thank you to the respective makers of these great expansions: Matze (Matthias Heinrichs) from a1k.org. I don't know who designed the SCSI2SD but here is it's project page. The joystick adapter is sold by eBay seller 24Mata. Matze also made an adapter like this.