On Fri, Apr 19, 2013 at 9:31 AM, Ed Jaffe <[email protected]>wrote:
> I saw a discussionon IBM-MAINrecently about how many MVS TCBs was "too > many" MVS TCBs in an address space. > > System control blocks like TCB, located in LSQA below 16MB, will likely > never be moved above 16MB since it's still possible for a 24-bit program > to load PSATOLD and reference GUPI fields in the TCB. > > This got me wondering about just how much AMODE(24) code is still out > there--not only for z/OS but for other operating systems as well. Any > ideas? Are most programs still 24-bit? Half of them? Ten percent or less? > > For my employer there is a substantial about of simple batch COBOL and Assembler program that are amode(24). They are not converted to amode(31) because a) work effort required to recompile/assemble and test; b) certain old programs whose source code is lost are amode(24) and are called by many other programs. There is no business case to modify so they stays the same. The dev staff does not have time to "fix" this because of the volume of business change requests far outweighs the ability to update programs for issues like this. We only specifically converted 1 set of program to amode(31) because that job was running out of below the line memory. And it was an important job. > -- > Edward E Jaffe > Phoenix Software International, Inc > 831 Parkview Drive North > El Segundo, CA 90245 > http://www.phoenixsoftware.**com/ <http://www.phoenixsoftware.com/> >
