CONTR47@NOSC-TECR.ARPA (01/31/88)
1. regarding question about whether someone has coded a 64 bit integer package for a 32 bit 2s complement machine I would point out that in the 60s we coded 32bit integers for 16 bit 2s comlement machines. I wonder if maybe there could be similarity? Nooo! Probably not. --- 2. Booch Diagrams are not a joke, unless of course you produce a flat design with 400 subprograms and try to represent the entire design at once. Of course noone would do that - more than once. Sarcasm aside I believe that the difference between software engineering and programming is that the software engineer puts Booch diagrams together like Leggo blocks to build a software sytem and the programmer hand crafts each block. The Booch diagram is a way to represent the structural aspects of a software system and Ada then allows one to represent that same structure to the computer. The Booch Diagram does not replace the data flow diagram, control flow diagram or flow chart or Petri net etc. etc. but does allow one to express to other humans the structural aspects of software written in Ada. For the past year the first vugraph I use in my Ada Software Engineering course has at the center a large circle representing the Ada library. I show how pieces are put into library, and among other things, how they are combined into "build threads" to produce a software system. Of course we go on to the details of "Ada pieces" and then Booch diagrams are a nice way to represent the structural and dependency relationships among those Ada "parts". With some seriousness I am formulating my "parts-is-parts" approach to computer system design. e.g.: The system engineer uses hardware parts from the production line, say IBM PC compatible things, and uses software parts from the Ada production line when there is one. We must learn how to do this but when we do the cost of computer systems should be about 1% of what it is today. Sorry I got so far afield of Booch Diagrams. More later. regards, sam harbaugh ---------------------