<snip> when I looked at the registers in TEST none had the high order bit on </snip>
I suggest that you read the principles of operation description of program interrupt x'38'. When in AMODE 64, all of bits 0-32 are relevant. The high bit that you refer to, presumably, is bit 32 of the 64-bit GR. If bit 32 is off, then at least one bit amidst 0-31 is on. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN