Originally Posted by etabeta78
are you sure it's a BASIC .cas and not a machine language .cas?

the former must be loaded with CLOAD the latter needs you to enter SYSTEM. see here for instructions

http://classic-computers.org.nz/system-80/driving_instructions.htm

(instructions refer to system 80, a trs80 clone, but they work as well on a color genie)

Yes, the loading process for machine language based software is different (SYSTEM). I tried too, without success.