3.0 PROCEDURE OF DISCUSSION #

3.1 #

The classification of 2.0 being completed, it is now possible to take up the five specific parts into which the device was seen to be subdivided, and to discuss them one by one. Such a discussion must bring out the features required for each one of these parts in itself, as well as in their relations to each other. It must also determine the specific procedures to be used in dealing with numbers from the point of view of the device, in carrying out arithmetical operations, and providing for the general logical control. All questions of timing and of speed, and of the relative importance of various factors, must be settled within the framework of these considerations.

3.2 #

The ideal procedure would be, to take up the five specific parts in some definite order, to treat each one of them exhaustively, and go on to the next one only after the predecessor is completely disposed of. However, this seems hardly feasible. The desirable features of the various parts, and the decisions based on them, emerge only after a somewhat zigzagging discussion. It is therefore necessary to take up one part first, pass after an incomplete discussion to a second part, return after an equally incomplete discussion of the latter with the combined results to the first part, extend the discussion of the first part without yet concluding it, then possibly go on to a third part, etc. Furthermore, these discussions of specific parts will be mixed with discussions of general principles, of arithmetical procedures, of the elements to be used, etc.

In the course of such a discussion the desired features and the arrangements which seem best suited to secure them will crystallize gradually until the device and its control assume a fairly definite shape. As emphasized before, this applies to the physical device as well as to the arithmetical and logical arrangements which govern its functioning.

3.3 #

In the course of this discussion the viewpoints of 1.4, concerned with the detection, location, and under certain conditions even correction, of malfunctions must also receive some consideration. That is, attention must be given to facilities for checking errors. We will not be able to do anything like full justice to this important subject, but we will try to consider it at least cursorily whenever this seems essential (cf. {}).