Being safe on the internet (was Re: Here we go again - ISP DPI, but is it interception?)

Tom Thomson colinthomson1 at
Mon Aug 9 14:11:09 BST 2010

Peter Tomlinson wrote:
> The memory stirs, taking me back to 1968 when I designed the very simple
> memory management hardware for the ICL 1904A (and in the process fixed
> an error in the 1906A's MMU). Took the software people another 2 years
> to get George 4 running. So that was old-fashioned, was it, Tom? It was
> state of the art then, in the commercial environment that soon after
> took a wrong turn...

No, I don't think the 1904A memory management system was old-fashioned in 1968, although machines with safe memory management had by then been around for at least 5 years, for example both versions of Atlas antedated it and were in some respects more advanced (as was the memory management on its contemporary English Electric 4-75) and at least some 360s that predated it had decently secure memory management.  The disasters didn't happen until quite a few years later when the segmented memory and hard distinction between programme and data of early mini-processors (such as the CTL Modular 1) went out of fashion, and new fashions decreed that memory management systems like those were the province only of that unfashionable creature "the mainframe", ICL with its 1900, System 4, and 2900 ranges, Burroughs, IBM and so on were all makers of those unfashionable mainframes, academic projects like Multics and MU5 were not trendy because they insisted on trying to do verifiable security somewhere near right, and even Intel (quite a bit more later) with its segmented memory  was undesirable (until MS decided to completely bypass the memory protection) compared to the fashionable exploitation of cheap hardware using cheap and sloppy programming standards.  
Was it a commercial pressure that brought us to a wrong turn, or was it the flight of the crowd towards the fashionable?  My feeling is the latter - I saw the pressures to follow fashion with good money being thrown after bad at doomed projects because they were thought to be fashionable, you must have seen that too. 


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