Back in 1990, I was pushing Assembler H to its limits and was invited to submit requirements for what became HLASM, being planned by John Ehrman. I was immediately impressed with his approach, which combined a strong vision of future possibilities with a very practical understanding of the real life requirements of compatibility, reliability and stability.
I still have a copy of the HLASM requirements and suggestions document that John created and maintained over many years, including quite a number of my own suggestions. Many of them were addressed long ago now, but we still have a huge collection of good ideas to follow up if we can find the resources! John was also involved in other areas such as working with the binder team on the GOFF (Generalised Object File Format) specification, which made possible a lot of new function to support Program Objects. (I later heard from John that I had apparently influenced some of this work myself when I visited the Santa Teresa lab in about 1988 and discussed possible orthogonal extensions to linkage editor function with Dick Lee of the binder team). I also worked with John more recently (via email and online chat) from 2014 until he retired in 2016, when we were both helping out with support of various old products such as VS Fortran (another of John's areas of expertise). I always appreciated his kind and wise help, and was happy to take on some additional support work to give him more time to work on his Assembler book. (I think that John had also hoped to create a similarly authoritative volume on writing macros once he had finished the first book, but although that never materialised, at least we have his excellent SHARE presentations on the subject). I'm sad that I never actually got to meet him in person (apart from perhaps a brief encounter at a SEAS conference in Edinburgh in 1987, of which neither of us had any clear memory), especially as both of us had outside interests in theoretical physics and classical music. John and Tineke had hoped to visit the UK for a vacation shortly after he retired, but his increasing need for medical treatment unfortunately ruled that out at the time. Many others will have encountered him at SHARE conferences or education sessions, where he clarified the mysteries of HLASM and the binder (among other topics) and helped many on their way to become better assembler programmers. As current HLASM team leader I am reminded every day of John's influence on the product, although he did set the development team some tricky challenges which we are still trying to get right to this day, such as removing some awkward restrictions on built-in functions and avoiding ambiguities between SETA and SETB expressions, which we were still discussing by email less than a couple of months ago! He made a big difference. I will miss him. Jonathan Scott HLASM team, IBM Hursley, UK
