as far as I can remember from the syntax for im 0 on the 85, it doesn't execute code in the register, but uses the register as a pointer to the executed code, but I can't remember exactly where, I think it is at ii, which means with i=$0c it would execute code at $0c0c in the ram. Don't trust me completely on this but Jimmy Mardell's Gamewizard for Zshell did something like that.