Re: time-sharing history, Privilege Levels Below User

According to Lawrence D'Oliveiro  <ldo@nz.invalid>:

I'm quite sure that IBM would disagree with this statement.

>
I’m sure they would. But they invented virtualization in CP/CMS because
their attempt at an “interactive timesharing” system, CMS, was only
single-user.

There's no need to make up silly stories like this when the actual
history is so well documented. CP/CMS was the IBM Cambridge Scientific
Center's response to the end of CTSS and the loss of the bid to build
Multics. CP and CMS were developed in tandem and it was always a
time-sharing system, originally on a modified 360/40, later on a
360/67.

For a long time IBM insisted the real time-sharing system was TSS,
then later TSO on MVS, while CP was just an unsupported lab curiosity.
Eventually they gave in to the obvious, renamed it to VM, ported it to
S/370, and made it a real product.

The Wikipedia article has lots od details  https://en.wikipedia.org/wiki/History_of_CP/CMS

As does this IBM paper on the history of VM https://www.vm.ibm.com/history/50th/vm370ori.pdf
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