Referring to architecture, algorithms, language features, etc obviously. They were all better on many machines from 1960&#x27;s-1980&#x27;s. Market kept rejecting anything that wasn&#x27;t backward compatible with existing garbage and had max performance per dollar. So, dumb CPU&#x27;s, COBOL, and C it is. :)<p>Gave examples of what features old ones had in the essay below with the first link mentioning the specific systems for further inspection:<p><a href="https:&#x2F;&#x2F;www.schneier.com&#x2F;blog&#x2F;archives&#x2F;2014&#x2F;04&#x2F;dan_geer_on_hea.html#c5598568" rel="nofollow">https:&#x2F;&#x2F;www.schneier.com&#x2F;blog&#x2F;archives&#x2F;2014&#x2F;04&#x2F;dan_geer_on_h...</a><p>Note: B5500, System&#x2F;38, and Ten15&#x2F;FLEX are all especially worth considering. Two were basically HLL machines with type-safety and interface safety enforced at hardware level. System&#x2F;38 was object-based with HW- and SW-level protections plus portable microcode layer.<p>I&#x27;d say Channel I&#x2F;O counts as one that kicks modern systems&#x27; asses. Servers have been copying it bit by bit over past ten years, maybe even exceeding it, but server OS&#x27;s are inherently inferior in usage given mainframe OS&#x27;s are designed for I&#x2F;O offloading at core. Near interrupt-less architecture with acceleration engines makes many apps <i>scream</i> with performance. And would only cost $10 per CPU on desktops but would require Windows &amp; Linux rewrites. (sighs)<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;I&#x2F;O_channel" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;I&#x2F;O_channel</a>