34. The system of claim 24 wherein the computer system includes a user-operated text editor for editing the one or more instructions of the source program in the high-level text-based language.
35. The system of claim 34 wherein the conversion means is responsive to the user-operated text editor to automatically convert the one or more instructions of the source program in the high-level text-based language into the first corresponding instructions in the ladder-based language if the source program is edited.