Dave Clark wrote <snip> is there some other means of knowing whether or not to save the high halves in the caller's save area? </snip>
This has been covered many times. It's your interface. If you documented that they should provide a save area suitable for saving high halves in that area then you assume that they have met the interface requirements. If they didn't (especially with respect to save area), bad things will happen. It's no different than if you required a 72-byte save area and they gave you a shorter one. Dave Clark wrote <snip> I found that a "standard register save area" is now defined by IBM as 128 bytes long. </snip> For z/OS, no it is not. I have no idea about z/VSE. Michael Schmitt wrote <snip> The problem is that the new save area formats are not compatible with the 72-byte save area format, so you can't use them in amode 31 unless you control both the calling and called programs. And they're not supported by Language Environment. </snip> Yes they are compatible (to the extent that is important) and you can use them in any AMODE. You can chain backwards, interpreting the information saved at offset 4. You cannot forward-chain. Peter Relson z/OS Core Technology Design
