[Info-vax] OS implementation languages

[Bob Eager]

On Sat, 26 Aug 2023 13:44:55 +0000, Dan Cross wrote:

> In article <kksieaF4cdU2 at mid.individual.net>,
> Bob Eager  <news0009 at eager.cx> wrote:
>>On Fri, 25 Aug 2023 17:38:31 +0100, Roy Omond wrote:
>>
>>> On 25/08/2023 14:14, Bob Eager wrote:
>>>> On Thu, 24 Aug 2023 17:39:41 +0000, Simon Clubley wrote:
>>>> 
>>>>> That's seriously interesting thanks. So, contrary to what some are
>>>>> saying,
>>>>> the idea of writing an OS in such a way was well established by the
>>>>> mid-1970s. (I'm going off historical documents and the recollections
>>>>> of people here as in the mid 1970s I wasn't even in secondary school
>>>>> yet. ).
>>>>>
>>>>> One thing of interest above is you say the OS itself was also
>>>>> written in this language. Are you referring to the kernel-level code
>>>>> here or something else ?
>>>> 
>>>> And starting in 1966...
>>>> 
>>>>   http://www.ancientgeek.org.uk/EMAS/EMAS_Papers/
>>>> EMAS_The_Edinburgh_Multi_Access_System.pdf
>>>> 
>>>> Or for my lecture on it (I was involved, as you will see):
>>>> 
>>>>   http://www.bobeager.uk/emas/
>>> 
>>> Just adding another toot of the horn.  I am an Edinburgh Computer
>>> Science graduate, so my early background is EMAS and its
>>> implementation language IMP, both of which I still miss today.  A good
>>> number of my class colleagues ended up at DEC (remember Spiralog ?).
>>
>>I am looking at resurrecting EMAS. There are IMP compilers around,
>>still.
>>Someone I know has written a viable IMP to C translator.
>>
>>And you may find the end of my lecture rather interesting.
> 
> That would be interesting. One wonders if an initial target may be an
> ICL 2900 emulator?

It would indeed. The emulator is in progress; I currently have a compiler 
bug I need to fix. See the lecture for more details.

> I understand that EMAS was ported to 370/XA; would
> it boot under Hercules?

It would, but there are incomplete sources. I was the only person to 
preserve sources, and they are for 29800 (the lecture explains why). 
Incidentally, I did quite a bit of the XA porting. That was to a 4381.

> Interesting, the EMAS virtual memory subsystem was ported to Unix in the
> 80s by Charles Forsyth at the University of York. He wrote a rather
> interesting paper on this that you may find interesting:
> https://www.terzarima.net/doc/taste.pdf

Yes, I will certainly have a look at that!