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by rbanffy
2103 days ago
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Apple is (and has always been, really) a systems company. They sell hardware that may or may not run other system software, but they sell it as a bundle. Interestingly enough, Jobs' move ending licensing of MacOS to third parties is a lesson learned by IBM a couple years earlier, not with their PC, but with their mainframes. Their mainframe OS is licensed in terms similar to Apple's macOS: it can't run on non-IBM hardware. IBM did this at the point they realized others, such as Amdahl, could build mainframes that ran IBM software faster and cheaper than IBM hardware. IBM would be giving up a sizable portion of their profits if they allowed that and thus they didn't. The last ancestor of z/OS you can run on non-IBM hardware is MVS 3.8j. Controlling both hardware and software roadmaps allows IBM to use one as a force-multiplier for the other. The death of the mainframe has been predicted since the 80's and doesn't seem to be any nearer now than it was then. It'd be fair to point out that Jobs could have learned this lesson without IBM's help - as NeXT was failing, it wound down its hardware business to sell its OS and other software to run on other hardware and operating systems. At that point, it couldn't innovate like they did with their workstation with MO storage (which was a bad idea) or the built-in DSP (which was a good one). They would have to differentiate on software alone, something that's much, much more difficult to do. |
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MVS 3.8j was, however, the last version of MVS that was both available from IBM without a license and which lacked copyright protection under which IBM could prohibit unrestricted use.
And, to be perfectly pedantic, a number of z/Architecture "clones" now exist in the form of software emulators — including at least one[1] developed and sold by IBM itself — and these are perfectly capable of running more recent z/OS releases, possible license complications notwithstanding.
[1] https://www.ibm.com/products/z-development-test-environment