[Simh] VAX/VMS

[Paul Koning]

> On Feb 16, 2016, at 9:56 AM, Timothe Litt <litt at ieee.org> wrote:
> 
> ...
> Nonetheless, Brooks (@IBM) definitely gets credit for the first
> commercial line of architecturally (forward) compatible machines.  Prior
> to that inspiration, every new machine was unique and most software
> started over (including compilers).

I'm not sure that "first" is accurate.  If in the sense of a series of machines for which that feature is specifically marketed, perhaps.  But the PDP4/7/9/15 is another example that started somewhat earlier.  (PDP1 doesn't quite match, as I understand it.)  CDC 6000 series definitely fits your definition, and those came out at the same time as the 360.  The Burroughs B5000 series is somewhat older (1961, says Wikipedia).

Not as well known and perhaps not quite close enough to be called "forward compatible" are the Electrologica EL-X1 (1958) and EL-X8 (1964), with more planned but not shipped before the company was bought & closed down.

Of all those, the IBM 360 descendants are perhaps the most commercially successful, and also probably the longest lived.

	paul