Is there someone from HobbyRetro (who I bought it from) on this forum, or the designer of this device (SDMMR 1024K)? I would like to get this cartridge working.
Got it working now with the help from Hobbyretro. Cleaned the pins on the cartridge with alcohol and it was quite dirty. Didn't expect I had to do this on a brand new item. But I can now enjoy using it.
Having 512kb mapper and megaram at the same time definitely makes this device more useful than the older model. I don't have the old one, but on a 64kb msx machine I can imagine that one would not have the disk (sd) access when using in megaram mode as the nextor needs 128kb.
but you had to clean the contacts afterwards…