The syntactic definition of a language used for analytic differentiation is presented in this paper. The definition is given in Backus normal form. A translation is then added to this definition so that the derivative of any algebraic expression written in the language can be obtained by using the syntax-directed compiler developed by E. T. Irons. The mathematically inelegant form of the derivatives obtained leads to changes in the original syntactic definition of the language. The language is simultaneously extended in order to obtain: (1) derivatives of higher order, (2) partial derivatives, (3) the derivatives of implicit functions and (4) the derivatives of any number of functions at the same time. The output of the compiler is the solution of the original problem and not an intermediate-language program to be assembled and executed. This, it is felt, represents a new use of compilers. Also, using Backus normal form rather than assembly language facilitates the programming, checking out and changing of programs. The principle of extending the syntax of any language in order to obtain a more efficient translation is discussed.

This paper presents the results of an attempt to automate part of a formalized method of system design. Basic to this method are two languages, Boolean algebra and a register transfer language. From a Boolean algebra description a digital system can be constructed while the second language can be used in a step by step description of the execution of each instruction. To illustrate, a register transfer language is used to give a description of an adder considered as part of a digital system. This description is then translated into a set of Boolean equations. Next, the automation of this translation by using a syntax-directed compiler is explained. The compiler requires a syntactic description of register transfers. This description is given using a meta-language called Backus normal form. A Backus normal form description of Boolean equations that is used for translating Boolean equations into register transfers is also given; this translation process is called analysis. The feasibility of computer-aided design and analysis is thereby demonstrated. The computer-aided design method described in this paper, besides eliminating drudgery and error, would permit several system designs to be attempted and evaluated; a permanent record of the chosen system would also be available for future modifications, maintenance, and simulation. The analysis programs could be used to check the effect on the system of any changes made in the Boolean equations (or equivalently the logical diagrams) and the effect of any unused operation codes.

In this paper the system design of a 250 Mc tunnel-diode computer is presented. To resolve the disparity between the obtainable arithmetic and main memory speeds, a sophisticated advanced control is used. The advanced control fetches instructions and operands from the main memory before they are actually needed by the arithmetic unit. These instructions and operands are stored in two small, high-speed tunnel-diode memories which are called queues. A third queue, the Storage Access Queue, is used for saving a storage access request if it cannot be serviced immediately. Hence, advanced control is split into four parts, the Instruction, Operand, Store and Arithmetic Controls, which operate independently (except for appropriate interlocks) of one another. In the design of any computing system which has advanced control, care must be taken to prevent the old value of a memory location from being used instead of a recently computed value. The proposed system insures that the latter is always used and in this respect the system appears as a conventional computer to the user. However, the system is not entirely conventional in its appearance; the use of a stack in place of the accumulator in the arithmetic unit is proposed. The arithmetic, modifier and input-output units are all designed to operate independently of one another and execute simple algorithms at high speeds. This permits the system to be built with an estimated 12,000 tunnel diodes and four 8000 word sections of memory. The system is expected to operate at very high speeds.