[Info-vax] OS Ancestry

[Arne Vajhøj]

On 5/17/2021 8:59 AM, Chris Townley wrote:
> On 17/05/2021 13:22, Arne Vajhøj wrote:
>> On 5/17/2021 8:18 AM, Simon Clubley wrote:
>>> On 2021-05-15, <kemain.nospam at gmail.com> <kemain.nospam at gmail.com> 
>>> wrote:
>>>> Another pretty good link for those looking for VMS history:
>>>>
>>>> <http://gordonbell.azurewebsites.net/digital/Bell_Retrospective_PDP11_paper_ 
>>>>
>>>> c1998.htm>
>>>>
>>>> "A Retrospective on What We Have Learned From the PDP-11:
>>>> What Else Did We Need to Know That Could Have Been Useful in the 
>>>> Design of
>>>> the VAX-11 to Make Alpha Easier?
>>>>
>>>> "VMS is the Architecture That Mattered. not PDP-11, VAX, or Alpha"
>>>
>>>  From that link:
>>>
>>> | Thus, our real oversight was not understanding that VMS should have 
>>> been
>>> | built on the C machine for portability across any architecture.
>>>
>>> This. 5 zillion times this. VMS could have become like Unix in dominance
>>> if this had been the case.
>>>
>>> Want to move VMS to a new architecture in this setup ? It would have 
>>> been
>>> a comparable effort to what is involved in porting Linux to yet another
>>> architecture, instead of the current effort that is involved.
>>>
>>> VMS was designed at too low of an abstraction level.
>>
>> But it is worth remembering that back then (second half 1970's) then
>> it was not common to write OS in C. Assembler and proprietary languages
>> was common. That changed in the next 10-15 years.
>>
>> But that one would be better off if one was able to predict the
>> future 10 years out is rather obvious.
>>
> Didn't Unix change that? Was it not built in C from day 1?

Unix was supposedly first written in assembler and a few year later
rewritten in C.

But it was in C when VMS was created.

The point is that at that time then Unix was not a big thing.

IBM, CDC, Sperry, Burroughs, HP etc. all had non-C OS.

Arne