I worked with Mike in 1977 when he was he was assigned to mentor me as a gap-year student working at Hursley. He was a rock climber and I recall many discussion

I worked with Mike in 1977 when he was he was assigned to mentor me as a gap-year student working at Hursley. He was a rock climber and I recall many discussions about the physics of ropes and what happened when/if you fell and the rope broke your fall. There are all sorts of interesting effects that happen when the rope "goes tight" and the waves that run up and down the rope as it stretches (both elastically and inelastically). We worked in Product Assurance (IBM's terminology for QA). We built hardware to test the system that was under test. We often worked the night shift as the developers got the working system during the day! I don't recall Rexx from those days, so I think it came after 1977.