[Info-vax] Creating an open source version of VMS, was: Re: OpenVMS Hobbyist Notification

[Arne Vajhøj]

On 3/11/2020 9:25 AM, Simon Clubley wrote:
> On 2020-03-10, Arne Vajhøj <arne at vajhoej.dk> wrote:
>> 20 million lines of code => more than 20000 man months of effort
> 
> Assuming that figure is accurate, a major chunk of that is Macro-32.
> 
> Code written in a higher level language will be smaller,

30 year ago it was said that VMS was 1/3 Macro-32 1/3 Bliss and 1/3
other stuff (mostly HLL).

But the VMS code increased in size and I suspect lot of C was added
for new stuff (especially if based on external code).

20 years ago it was said that VMS passed the 25 million lines of code.

25 MLOC + the work done last 20 years - big reduction for Macro-32 to C 
- some reduction for Bliss to C

I guessed that would end up around 20 MLOC of C.

I have never seen the VMS source kit, so I am guessing based on
the gossip (mostly here).

It is actually not that much after todays standard.

Linux is about 25 MLOC kernel + 25 MLOC user land + 25 MLOC GUI
today I believe.

Windows exceeded 60 MLOC with Vista and must be much bigger today.

>                                                     easier to write
> and will have additional compile-time error checking by the compiler.

Absolutely.

But with the coding willingness in the VMS community then I would
consider anything beyond 100 KLOC unrealistic.

Arne