46. The system of claim 42 further comprising: first signal producing means, in communication with the user-operated ladder-language editor, to produce the first signal if the source program has been edited by a user using the user-operated ladder-language editor, wherein the second conversion means converts the first corresponding instructions into the second corresponding instructions after receiving the first signal.
42. A system for developing a source program bilingually and generating a control program therefrom utilizing a computer system, the control program being executable by a controller to control the operation of one or more devices, the system comprising: receiving means for receiving one or more instructions of the source program in a high-level, text-based, non-machine language; first conversion means, in communication with the receiving means, for converting the one or more instructions of the source program into first corresponding instructions in a ladder-based language; a user-operated ladder-language editor, in communication with the first conversion means, for editing the first corresponding instructions of the source program in the ladder-based language; second conversion means, in communication with the user-operated ladder-language editor, for converting the first corresponding instructions, as edited, into second corresponding instructions in the high-level text-based language; a user-operated text editor, in communication with the second conversion means, for editing the second corresponding instructions of the source program in the high-level text-based language to form an edited source program; and a compiler which compiles the edited source program to form the control program.