Mainframe, MVS and zOS Discussion

hi,

For a company to have a mainframes - what are the advantages of mainframe? Why are they still using mainframes? Why don't they switch over to latest technologies like j2ee, .net?

Why don't they switch over to latest technologies like j2ee, .net?

You tell us why they should

I just thought it might be wise to go that way though I don't have a full proof study with me but asked a question from a novice point of view. But why do you get evil?

because even if You are a novice You should know that
mainframe is a HARDWARE platform
j2ee, .net are SOFTWARE platforms

I realized that mention about terminologies that way was not correct but I meant that technologies used on mainframes and Windows technologies. Though JAVA etc. work on Mainframes as well but frameworks like .Net are not available on Mainframes. One thing of not going for this shift, possibly, can be that there is a lot of code on Mainframes still in use, but is this the only challenge or there is more to it?

Stability and size of application are other possible reasons to use a mainframe. When we did a program age study a few years ago, the oldest program running on our mainframe was last compiled in 1977 and quite a few had compile dates of 1985 or earlier. Upward compatibility of IBM mainframes is not a myth. Try running a Windows program from 10 or 20 years ago and see how far you get (probably not very far). And mainframes can be anything from a small hardware platform to a very large hardware platform -- and all IBM mainframes are designed for performance. My site would run with the CPU at 100% for 2 or 3 days at a time during month-end processing. Many Unix / Windows systems start having problems once CPU usage gets over 20% for more than a few minutes.

Thanks Robert.