Oh, yeah, your hardware definitely has issues, then. If so, I'm rather suprised that the DEC diagnostics didn't pick it up. You're stu^H^H^Hbrave! Yeah, probably your process wound up at a different place in physical memory (although there are a zillion other ways one could get that effect, depending on exactly what the issue is - e.g. maybe a bad bit in the memory word where the process table happened to wind up). The 'ls' one, please (shorter/simpler); I can poke around in that, and see if I can find any clues as to the cause. OK. I also have a little memory diag that I wrote myself that you could try. Let me know if you'd like it; it's currently for the /23+/73 (and it would probably work on the /70, I'd have to check) so I'd have to tweak a few things to get it to run on a /45. Best way to get it to you would be to send you the Unix assembler source, if you can get that onto the disk, then you could: as memptst.s mv a.out /memptst and just boot it. Noel