What ever happened to Tandem and NonStop OS 1976

Sure. That is the most convenient way to find all the obsolete instructions.

The whole point of this is to not have the code have to be executed in kernal mode. You do want the maximum amount of code to be in behalf of the user. It is the user who is going to have to make the decision to do the conversion work.

Well, note that if it's used that frequently, obsoleting it may not have been a bright thing to do. The reasons to replace an instruction is that the new instruction does things better.

Recompilation may not be a requirement. However, it is an aspect of a feature if there is a requirement. It means that the customer has to do a source check. I can't begin to tell you how many sources disappeared because the code worked well over a period of years. It meant that nobody had to use the sources for years.

So? You're suffering from bane short-term thinking if you consider this a negative. The fact that it does take a long time will encourage a transfer from the old to the new.

how many times we longed to do it the easy way but we were able to predict the huge mess after the easy way was shipped. When you think about these bit flows over time, it is no longer the easy way. I can almost claim it is never the easy way.

One of the rules of reexamining your buttumptions is "If it's too easy, there must be something wrong."

BAH