A different kind of Walter? :-)

[Georg Wrede]

Brad Roberts wrote:
> Alexander Panek wrote:
> 
>> Walter Bright wrote:
>>
>>> Alexander Panek wrote:
>>>
>>>> I'm sure going to spend some time getting a proper codebase for further
>>>> development done, and write some documentation about how to actually
>>>> get to the point of being able to write an operating system with D. I
>>>> think that's a major weak point of D, as it claims to be a systems
>>>> language, but there's no actual system written in it from scratch,
>>>> neither documentation on how to achieve that.
>>>
>>>
>>> Andrei suggested that the source code for Minix, which is fairly 
>>> small, could be transliterated from C almost directly into D. This 
>>> would neatly resolve the issue, and provide a starting point for 
>>> anyone wanting to take it further.
>>
>>
>> True. On the other hand, a kernel written purely in D is something 
>> that really would (and will, arr) be cool! I just find it less 
>> exciting to code "C with D", so to speak.
>>
>> I'll make sure to announce the project, once a few milestones are 
>> finished, on the newsgroups.
> 
> 
> Pardon the curmudgeon in me, but aside from being educational and being 
> able to say 'see, someone's done it', what is to be achieved from 
> inventing yet another kernel? 

The advertising value is simply enormous.

A lot of car makers (the smaller, the likelier) have always had some top 
models that give the brand prestige. Those cars were sold in very small 
numbers, and they made losses with them. But that was on purpose, 
because the prestige value sold much more "regular cars". I've seen it 
with motorcycles, cameras, watches, liquor, perfumes, and in service 
marketing!

In the 80's many companies had doubts about Turbo Pascal. But when 
Borland demonstrated that it was not only possible but downright 
straightforward to write a TSR with it, the acceptance was huge. It 
became a Serious Programming Language.

Oh, and speaking of cameras, somebody buying a camera wants it to have 
all the bells and whistles, even when they never end up using them. But 
they /have to be there/.

>  Anything beyond a toy kernel is an _enormous_ effort.

We don't have to beat Linux. All we need is to have a valid 
counterargument when the [yourLanguageHere]weenies start saying D is not 
for systems work.

Besides, the tinier the merrier. A small (e.g. Minix like) actually 
running OS (even if totally toy) is a good vehicle for trying out all 
sorts of things, without having to buy Annotated Linux Kernel Source 
Code ($200) or even worse, having to read it through only to test your 
little kernel heap algorithm.



---



For the less-than-midle-aged of us: a TSR (Terminate and Say Resident) 
was a killer technology of the time. Microcomputers (as "PCs" were 
called, emphasizing their laughable lack of memory and horsepower -- as 
opposed to Minicomputers, Computers and Mainframes) were single-user 
single-tasking, which effectively meant that you can't start a 
calculator while you're in the text editor, or make notes or look at 
your calendar while in e-mail (yes, we had e-mail at the time, in Europe 
too, before the WWW, or even before the Internet, or Usenet became 
available).

A TSR let you switch between two tasks, usually with some special key 
combination (like pressing both shifts or Ctrl-shift), and that was 
implemened with a wedge into the keyboard interrupt routine. Yes, you 
could have several TSRs running and switch between all of them -- if you 
were savvy. There was even a "multitasking" app, called Software 
Carousel, which let you run arbitrary programs while the others were 
suspended. But that came much later.

But the notion of TSR was common with the CP/M operating system (that 
the world used until PC-DOS (and later MS-DOS) usurped them) way before 
Bill got into the OS-game.