[Info-vax] Alternative _legal_ operating systems for VAX ?

[Arne Vajhøj]

On 1/2/2022 4:24 PM, Johnny Billquist wrote:
> On 2022-01-02 22:01, Arne Vajhøj wrote:
>> On 1/2/2022 1:36 PM, Johnny Billquist wrote:
>>> On 2022-01-02 16:11, Arne Vajhøj wrote:
>>>> Alternatively you could take up the Linux VAX port. Some
>>>> work was done many years ago and I believe they got pretty
>>>> far.
>>>
>>> I think it booted to single user mode. Not sure it got much further. 
>>> Not sure anyone would even want to try and pick that up, as Linux is 
>>> constantly changing under the hood, making it a big task to resume 
>>> something abandoned years ago.
>>
>> Remember that Simon believes using C makes porting easy.
>>
>> Great opportunity to demonstrate.
>>
>> :-)
> 
> Well, this has close to nothing to do with C.
> If the API is changed, it's a headache.
> And porting operating systems requires a lot of code to deal with the 
> specifics of the hardware, which is inherently not that portable.
> 
> And thus - if you have code that deals with the hardware, but which is 
> using an API that no longer exists, you need to either rewrite all the 
> code that deals with the hardware, or rewrite all the code that makes 
> use of the API to the rest of the OS, which might also force changes in 
> code that deals with the hardware.
> 
> Makes no difference which language you are working in, and no matter how 
> easy a language would be for porting, the problem here don't change.

If it was easy then it would already have been done.

:-)

> All that said, I actually do believe that C is easier to port than 
> Macro-32. :-)

I agree.

Arne