[TUHS] Re-implementations/Clean-Rooms et al.

[Larry McVoy]

So there is this thing that us old people do that old people did to us.
Go do it, kid, you can do it.

It doesn't always work but it works way more than you might think.
I was one of those kids where it worked.

On Thu, Sep 08, 2022 at 08:52:57PM -0400, Steve Nickolas wrote:
> On Thu, 8 Sep 2022, Larry McVoy wrote:
> 
> >On Thu, Sep 08, 2022 at 08:05:44PM -0400, Steve Nickolas wrote:
> >>
> >>I'm probably the only one brazen enough to put it to the test.
> >>
> >>For some years, I've wanted to create a free implementation of System V, and
> >>then move on from there.  (I know there's limited utility for such a thing,
> >>because of the BSDs.)
> >
> >Why?  Have you booted 32V?  Run in it for a while?  No VM, no networking,
> >very basic system.  Other than historical, I don't understand the point.
> 
> Wasn't so much about 32V itself, as 32V being potentially clear and the
> source for a lot of SysV, that having 32V would make rewriting SysV a lot
> easier. ????
> 
> I've used v7/386, which is probably a comparable system.
> 
> >>A few things actually hinge on this.  If it were considered a fact, and not
> >>a mere opinion, that 32V was PD, then I could be sure that certain things
> >>were safe to use, rather than having to rewrite (including some particularly
> >>tricky stuff the BSDs never fully reimplemented, like diff(1)).
> >
> >I'm a source management guy, I've written a couple of systems.  I live and
> >breath diff and diff(1) is not in the slightest way hard.  I wrote my own
> >version of SCCS in a way that you could get as many different versions of
> >the history as you wanted in one pass.  That's a lot harder than diff(1).
> >
> >But maybe I don't understand what you think is tricky about diff, you
> >may have some insight I'm missing, care to share?
> 
> I'm not actually that good a programmer.  Step me through an algo, I can
> probably interpret that as C, BASIC, 6502 ASM or 8086 ASM - but whether I
> can implement it from just an explanation, that's hit or miss.
> 
> Frequently I come up with stupid ideas that I think are beyond me, and often
> I'm right.  Once in a while they're not, and I'm able to actually implement
> something.  ????
> 
> Stuff like diff or sccs might be easy for some people here - but I've spent
> months wracking my brain on things I think are simpler (6502 CPU core for
> example - which is why for 20 years I used others' cores) and been
> fruitless.
> 
> -uso.


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Larry McVoy           Retired to fishing          http://www.mcvoy.com/lm/boat