robinsonb5 : thank you for providing the other cores. I've tried them out, but with the non-working OSD_CA01.sys file. Both also result in a red screen.
When I remove the non-working OSD_CA01.sys file both cores do show a blue screen, but of course, there's not much to see then.
I am using the TCv2 in cartridge mode connected to a C64 Reloaded MK1 with the power supply that came with it. I've also tried it in stand alone mode powered through a laptop. There's no difference with the cartridge mode.
Furthermore, I've tried unpacking the non-working OSD_CA01.sys file with another program (WinZip), but that made no difference.
I've tried the two cores with the working OSD_CA01.sys file and then they work fine, but Workbench still doesn't show any fast RAM.
I've also tried Zeewolf 2 like that, but that doesn't seem any quicker. Certainly not in cartridge mode. I cannot test this in stand alone mode very well, because I don't have a docking station and therefore cannot connect any joysticks.
Finally, with these two cores the video settings aren't garbled like the first core. I've saved a configuration and when I load up that configuration with the first core first and then access the video settings, then they aren't garbled. Of course this is all with the working OSD_CA01.sys file.
Weird that I get a red screen with the non-working OSD_CA01.sys file and others don't seem to.