CIRCLE WITH A DOT

@SteveBellovin @stuartmarks @aka_pugs @JohnMashey All of which (punch card focus, overloading high order pointer bits, packed decimal, 6bit bytes, scientific vs commercial, memory parity, two-speed memory) signalled the beginning of the end of an era where programmers and engineers counted every bit, every machine cycle and every memory reference. An era where programmers optimised hardware rather than round the other way.

While the need to deal with feeble compute power created interesting and novel architectures (Singer System Ten anyone? - https://en.wikipedia.org/wiki/Singer_System_Ten), the lock-in was a nightmare for customers embarking on their (oftentimes first) tech refresh.

So sure, one can readily admire the S/360 design, nonetheless, its biggest contribution may have been as an extinction event for all those oddball architectures due to market dominance.

@SteveBellovin @aka_pugs If you were on the non-EBCDIC side of the fence you got the impression that IBM sales pushed EBCDIC pretty hard as a competitive advantage - even if their engineering covertly preferred ASCII.

The 32-bit word must have been a harder-sell for the blue suits since the competition were selling 60bit and 36bit amongst other oddballs.

Fortunately the emergence of commercial customers marked the declining relevance of scientific computing... Did IBM get lucky or were they prescient?

But yeah, the S/360 definitely marked the end of the beginning of computing in multiple ways.

@aka_pugs Really was the beginning of the modern era of computing, starting with the normalisation of 8-bit bytes and character addressable architecture.

Well, that's all true so long as we don't mention EBCDIC

@filippo If cooldown becomes common would that mean that supply chain attacks would mostly affect early adopters who presumably are more sensitive to the risks?