> But could an STCK(E) by a processor with a lower Programmable Field appear > incorrectly to come before a STCK(E) performed earlier by a processor with a > higher value?
No. There is a table in Chapter 4 of Principles of Operation that shows that for any two executions of STCK and STCKE on any CPUs in a system, regardless of which one is done first, the second value stored will always be greater than the first value, provided 1) both executions are in the same epoch and 2) any comparison involving STCK is done by extending the stored value on the right with zeros. It's only when STCKF is involved that you might get results stored by the second execution that are equal or even less than the first. - mb
