> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of john gilmore > Sent: Friday, April 23, 2010 8:28 AM > To: [email protected] > Subject: Re: Callin g unauthor ized code from an au thorized > a ddress spa ce > > Chris Craddock writes: > > | The big problem is that this platform has evolved over 45 > | years or so. Back when it started out nobody knew about | > integrity and there wasn't a lot of difference between the | > programming environment seen by the system and the > | application. As time passed things got a whole lot more > | sophisticated and vastly more complex, but the > | documentation didn't keep up. > > This observation and others that follow in that post describe > the present state of the world very well. > > I should, however, like to add a further comment, two related > ones really. > > The first is that IBM's OCO policy has greatly aggravated the > difficulty of learning what goes on within z/OS, and the > second is that the PLMs (Program Logic Manuals), Execution > Logic documents, and microfiche that one could once refer an > inexperienced person to are no longer made available as a > consequence of this OCO policy. > > It could be argued--although never, I think, very > persuasively--that there were compelling competitive > arguments for OCO when IBM had mainframe competitors, some of > them unscrupulous; but these arguments are now moot. > > This documentation alone was not itself enough, of course; > but it was enormously useful: Confronted by an uninformed > question, one could say something like, "Read pp. 35 to 57 of > the PLM first and then we'll talk". Time was saved; more > important, much elementary exposition that was likely to be > perceived as condescending could be dispensed with. > > Today there is such a gap in experience and detailed > knowledge between the young and the old that it is very > difficult to close even when there is goodwill on both sides, > which is not always the case. > > John Gilmore Ashland, MA 01721-1817 USA
>From my perspective, IBM wants/wanted OCO along with no PLMs mainly so that: >(1) customers would be dependant on IBM for system level enhancements; (2) >ISVs who want to write system level enhancements would need to buy restricted >information, under an NDA; (3) internals could be changed with no impact to >customer code because the customer would not be writing to the "low level"; >(4) hardware could become more proprietary - e.g. how the system communicates >to an ATL is undocumented and so a competitor cannot use the same method, thus >increasing the cost to that vendor to implement their own method of >controlling their robot. This used to be true of OSAs until z/Linux required >that z/Linux source be released to satisfy the GPL. All the above helps "lock in" the z/OS user (other examples of this "lock in" are Windows and MacOSX). Without good documentation, it would be impossible for a vendor to write a compatable system so that z/OS binaries could run directly on their hardware. I.e. there will not be a WINE like system which implements a z/OS interface. Imagine the decrease in z/OS licenses if it were possible to directly execute z/OS binary programs on z/Linux. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets® 9151 Boulevard 26 • N. Richland Hills • TX 76010 (817) 255-3225 phone • (817)-961-6183 cell [email protected] • www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets® is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. –The Chesapeake Life Insurance Company®, Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM ---------------------------------------------------------------------- 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
