Oh, I meant the demonstration has lasted decades, not necessarily that the backwards-compatibility was eternal. Once you take the stance of preserving compatibi

Oh, I meant the demonstration has lasted decades, not necessarily that the backwards-compatibility was eternal. Once you take the stance of preserving compatibility, there's a strong market force to deprecate and eliminate old interfaces and guarantees once it's practical. On both the PC market of then, and the smartphone market of today, hardware gets replaced faster than once per decade.