>Empirical testing shows R0 is returned with a clean 64-bit address, even >for an old 24-bit program.
Of course there are other forms of LOAD (those that use SVC 7A). So a test of SVC 8 is not even a complete empirical test. And of course none of the IBM-Main readers would ever rely on an empirical test. The intent of the doc is to show that the 64-bit GR0 can be used as a BASSM target in all cases. I'll get it updated to make it clear that bits 0-31 are set to 0's for the AMODE 24 and AMODE 31 cases, and are not necessarily 0 for the AMODE 64 case when LOAD with ADDR64 was used. And if RMODE 64 is ever supported for normal LOAD, then the AMODE 64 case would change too. Peter Relson z/OS Core Technology Design
