I agree with Bill Fairchild. Do not presume.
If the documentation tells you just what is in the low byte then you must make no presumption about what is in the other 3 bytes (or the other 7 bytes if you want to go the 64-bit GPR route). Having said that, it might well be the case that if it has always been the case that those 3 bytes have always been zero, then in all likelihood we would keep it that way for fear of breaking erroneous programs. I do not have any idea if it has ineed always been that case. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
