On Sat, Sep 9, 2017 at 12:34 AM, Steve Johnson <scj@yaccman.com> wrote:
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At the time, the IBM 360 required that you run a special job step to create a file (we're talking punched cards here). And then you had to pull that job step out of the deck because trying to create a file that already existed was an error.
Point taken and sort of...TSS/360 and MTS was not (quite) as bad (although it could be if you use the batch processing system), but Steve is right... the idea of persistence was really not something people considered as 'easy' because it usually cost them money (real or allocated from the computer center).
So I suspect part of it was the economics of storage at time. On line (magnetic) storage was way more expensive than cards. Its has been pointed at the the original PDP-7 Ken used did not have a disk on it, it was custom special DEC's CSS group had splicing a PDP-15 disk to it. The disk unit itself was manufactured by someone else (as were most/many of DEC's disks for years).
Clay Christensen in "The Innovator Dilemma" has curves that actually start a few years later when he studies the disk drive industry. But its the just part of the same effect he is talking about.
The key is the what UNIX was doing was not considered practical by the mainframe folks, so people did not consider it. It was a resources to be protected (and to an extent, hoarded maybe). Moore's Law, et al, was the engine that allowed the UNIX innovation to really see light. The way the mainframes were doing things just did not make functional sense, but until it was economical to do it otherwise - we were stuck.
As Steve says... it really was mind blowing for making things like this easy.