At any stage when not at command level you can return to command level by typing CTRL(C) at the terminal. This is trapped by the operating system, and effectively generates an interrupt. So if you realize you are doing something stupid, you can stop by this method. Alternatively, if the computer is printing a long list (a file index for example) and you already have what you want, you can abort the operation with CTRL(C). In general a CTRL(C) return is treated as an error, so that the current DO-loop or script file is abandoned. Occasionally, when SPECX is outputting data to the screen, and for reasons I do not understand, it does not recover from a CTRL(C) interrupt and goes into a mode where it produces the same error message continuously -- just CTRL(Y) out of the program and start again.