That's a reasonable way to describe it. If I write an SVC, does that become then an extension of the OS? In a way, sort of.
-----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Thomas Berg Sent: Wednesday, August 30, 2006 12:59 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: What part of z/OS is the OS? This is of course a case with very blurred borders, but: * An OS is what is not an application * (but still software). Generally. For z/OS specifically, it maybe is the BCP as some suggest. The reason for this is that when You look at software in "all purpose" computers (in contrast to e g digital controlled amplifiers etc.), there is almost no general attribute that is unique for any type of programs. (Of course, e g a backup program could be said to have the "unique" attribute of the group "backup programs", but I don't consider here "backup function" to be a "general" attribute.) But there is only one group of programs that is not depending on, or requires another "lower" level of software. And which is also *never* useful alone. And which is always distributing CPU and memory resources to other programs. That group of programs is what I see as OS'. Thomas Berg -- ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html