IBM refers to all S360, S370, S390 and z900 series computers and their compatibles/clones as mainframes. The OSes they run are variants of either OS390 aka MVS (for Multiple Variable Storage - meaning it's named for its virtual memory capabilties, which were very, very new at the time it came out) aka zOS or VM/ESA aka z/VM (for Virtual Machine/Extended System Architecture).
They used to have water-cooling, now that's becoming commonplace; they used to take up a h*() of a lot of room (one or more rooms), now they are just bulky; they still lead the rest of the computing world in 99.999% RAS and in throughput, meaning that they can take an awful lot of IO thrown at them. The MVS family of OSes are primarily batch-systems, meaning you set them up with a massive chunk of data and they churn through it without batting an eyelid or bowling and eyeball; the VM/??? series are a more interactive set and have a set of guest operating systems, interactive and batch, running on them 99.999%. AS/400s are midrange, what used to be called minicomputers back in the days when DEC was still around - VaX is the another midrange, and so is Sun's SPARC and of course, the Alpha. Modern AS/400s are 64bit PowerPC machines; they used to have their own chip, which was a 48bit one; AS/400s have a virtual machine structure as well. AS/400s aren't compatible in any real sense with the S390/z900 family, though I don't doubt you can get some useful pointers from the books - IBM also runs Linux on the modern AS/400, in a separate "partition" to OS/400 - since OS/400 is a virtual machine's guest OS, all that is needed is to IPL (Initial Program Load) Linux and OS/400 in different virtual machines. Have I bored you to tears yet? ;) Wesley Parish On Wed, 11 May 2005 22:26, Shane wrote: > This thread started me thinking ... what is a mainframe? So i googled > and found ... > > A very large and expensive computer > <http://www.pcwebopedia.com/TERM/M/computer.html> capable of supporting > hundreds, or even thousands, of users > <http://www.pcwebopedia.com/TERM/M/user.html> simultaneously. In the > hierarchy that starts with a simple microprocessor > <http://www.pcwebopedia.com/TERM/M/microprocessor.html> (in watches, for > example) at the bottom and moves to supercomputers > <http://www.pcwebopedia.com/TERM/M/supercomputer.html> at the top, > mainframes are just below supercomputers. In some ways, mainframes are > more powerful than supercomputers because they support > <http://www.pcwebopedia.com/TERM/M/support.html> more simultaneous > programs <http://www.pcwebopedia.com/TERM/M/program.html>. But > supercomputers can execute > <http://www.pcwebopedia.com/TERM/M/execute.html> a single program > <http://www.pcwebopedia.com/TERM/M/mainframe.html#> faster than a > mainframe. The distinction between small mainframes and minicomputers > <http://www.pcwebopedia.com/TERM/M/minicomputer.html> is vague, > depending really on how the manufacturer wants to market its machines. > > Now I am really confused ... is a web server a main frame? It serves > many terminals. Is an Mac G5 a mainframe? It is classsified as a super > computer. is the four foot stack that constitutes a single sparc server > in my lounge a main frame ... is is encased in a frame with the > processors seperate to the hard drivers whixch are seperate to the power > supply which are ... > > Then I noticed the word expensive ... and immediately knew what a > mainframe is ... any computer loaded with MS Office Pro, MS XP Pro and > or Server 2003. Very expensive, especially if it is still able to run > and support multiple users and programs and terminals ( especially > terminals as you need to buy and expensive license per MS Terminal > Server Client). > > I wonder if MS knew it named its server so appropriately ... Terminal > Server (you die of bordom wiating for it or heart attack through the > frustration of using and maintaining it). They might as well have called > it the you will die server , the Tod Server, Death I ncarnate in > Software Server. ... > > Darn I must be sick ... where did that ramble come from. > > Anyway, what mainframe does this book claim to support? If it is an > AS400 or similar I might be interested ... > > Shane > > John Carter wrote: > > On Wed, 11 May 2005, Nick Rout wrote: > >> On Wed, 11 May 2005 14:20:15 +1200 (NZST) > >> > >> Wesley Parish wrote: > >>> Sounds like my cup-o'-tea! Looks like I'll have to visit Northlands > >>> A.S.A.P. ;) > >> > >> This is what we all love about Wesley, lives in Sumner, only transport > >> is a bike, > > > > He has a Bike. > > > > He has a Mainframe. > > > > He lives in Sumner. > > > > Shortly he will have Linux on a Mainframe. > > > > What more do you need in Life? > > > > > > ps: In this day and age of CD's and DVD's the difference between books > > and distros is remarkably small. Fr'instance, most books on DeadBat > > come with a disk or three full of DeadBat. So are they books or distros? > > > > The item in the warehouse is a book, whether it comes with a CD or not > > I don't know. > > > > > > John Carter Phone : (64)(3) 358 6639 > > Tait Electronics Fax : (64)(3) 359 4632 > > PO Box 1645 Christchurch Email : [EMAIL PROTECTED] > > New Zealand > > > > > > Somewhere on the edge of a Galaxy, one of literally billions of such > > galaxies, is a sun, one of literally billions of suns in that > > galaxy. -- Clinersterton beademung, with all of love - RIP James Blish ----- Mau e ki, he aha te mea nui? You ask, what is the most important thing? Maku e ki, he tangata, he tangata, he tangata. I reply, it is people, it is people, it is people.
