Tony's response deserves high praise, not least because it reflects some historical understanding of how systems evolve.
The original design of CICS envisaged making elegant use of the announced facilities of OS/MVT. When the time came to implement CICS 1) some of these facilities were not yet available and 2) some of them did not yet work reliably. The implementers of CICS were thus forced to take a RYO approach. They in effect gutted an MFT partition and installed their own functionally MVT-like facilities in it, calling their storage-management interfacing macros GETMAIN and FREEMAIN, etc., etc. The result was an in many ways a superb table-driven system, one that improved significantly over the succeeding years. Its chief 'defect' was the implementation of its user interfaces as a set of assembly-language macros, which meant that applications run under it had to be written in assembly language. This was 'remedied' in various ways, some elegant and some not, and finally by introducing a 'command'---as opposed to the old 'macro'---level CICS; ultimately it became possible to write CICS APs even in RPG, although these could not be even quasi-reentrant. The major marketing obstacles to its use by other than assembly-language programmers were thus gradually removed. In my own doubtless élitist view CICS never fully recovered from these initiatives. They did enable ribbon clerks to write CICS APs, and opinions about whether that was beneficial differ widely. What is not in my view open to argument is that criticism of the present state of CICS and other such subsystems that is not diachronic is all but certain to be irrelevant. We are all, ineluctably, creatures of our experience. If you don't know the history of CICS, IMS, DB2, whatever, mug it up if you wish to discuss that subsystem; and stai zitt' until you have mastered it. (Controversy will not thus be eliminated or perhaps even much reduced; equally informed views can, do differ sharply; quaint irrelevance will be reduced). John Gilmore, Ashland, MA 01721 - USA ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
