Job searching and AS/400, Computer Operations?

[scott at ehrlichtronics.com (Scott Ehrlich)]

I am a computer support/help desk/desktop support person by trade (10
years) upon graduating from college.   I'm doing contract work at the
moment to pay the bills, and my office is closing in June, thus an ongoing
job search.

Through my searching, I've come across various Computer Operations
positions, often involving monitoring systems, tape backups, and AS/400
experience, among other tasks.   I also am aware/believe it is more
machine than people-oriented.   I do like working with people, but I also
love mysteries and solving problems, and simply keeping people happy by
making sure things are running correctly.

That being said, what are people's insights of the computer operations
field vs desktop/technical support?   Along these lines, since I've never
used an IBM AS/400, would training/classes make sense?  If so, from where,
and what topics/areas?

Thanks for an education into this area.

Scott