Harvard vs. vonNeuman

Hi It is interesting that different people have different ideas as to what self modifying code is. Actually, the ability to load code and execute from a mass storage is self modifying. Code that uses a variable value for a table to look up execution addresses is self modifying. Most every multitasking system I've seen are self modifying. I think what people consider dangerous self modifying is when the program alters the actual execution instructions in memory and then executes them. It is strange that this form gets such a large amount of emotional negative response while other types are hardly considered issues. No matter how the code is written, one can make bad code in most any form. One can also make good code as well. There is no reason why self modifying code should be any more dangerous than any other type of coding if done with a complete understanding of what the limitations are. What is the difference between replacing one or two instructions and then executing them or replacing an overlay and then executing that overlay? Other than size, both are doing the same thing. One is forbidden while the other is normal operation. Dwight