I've worked a lot with more mid-range systems from IBM iSeries and pSeries. I'm having problems finding decent non-market-speak information on IBM System z/Mainframe. Yeah, I "get it" about consolidation and energy consumption and all that, but want to know some more on the internals.
Can anyone suggest a primer book (online?) that goes through the basics of the architecture, the basics of host and workflow management, maybe even how to execute Java (or Websphere?) direct?