I have ANSI=Yes and ANSIWin10=Yes. If I start TCC without issuing any commands (that means "/is" and nothing on the command line), it starts appearing as below. A few presses of "Enter", as I did below, doesn't change anything. But executing any command (noop below) sets things straight. If I let it execute TCSTART or give a startup command then the prompt looks good the first time.
