Re: Realtime/embedded project to help with employment.

[Dmytry Lavrov <m31415@mail.ru>]

Mark Lorenzen wrote:
> 
> "Luke A. Guest" <laguest@__n_o_s_p_a_m__abyss2.demon.co.uk> writes:
> 
> > On Mon, 11 Aug 2003 12:08:01 +0200, Mark Lorenzen wrote:
> >
> > > If you want to wotk with something that is "done rigth", then learn a
> > > good craft. Software will always be hacked together due to time
> > > pressure and management incompetence.
> >
> > Ok, I really cannot believe that the embedded side would be that bad,
> > surely planes, cars, etc. wouldn't be safe.
> 
> When I am travelling on the Metro (read: "underground") train here in
> Copenhagen I always consider myself lucky, because I have never seen
> the bleeding entrails of the software. The Metro is a driver-less
> system, but still monitored by real humans. I guess that if I knew the
> software, then I would be too scared and take a bus instead.
> 
> I do not trust software - not even the software that I write myself.

ESPECIALLY the software where i know sources,and more especially if i
write it myself. ;-)

I know one system where programs _may_(and may not) contain REALLY no
bugs.
It's very old "ussr programmable calculator"(i played with one).There
was versions with i/o ports(digital and analog ports) specially for
realtime.
Why program for this "platform" may have no bugs:
there is about 90 instruction maximal programm length(!!!),separate
instructions and data,and only 12 floating-point registers(no other data
storage except registers),and one 4-floats double ended queve (one
register of this deq are showed on "screen").
And it's all what you need for small programs like controlling almost
any conveyor(with some hardware-based help,of course) ;))).It was coded
in assembler,but opcodes was "designed" to make code length smaller.
It's possible to solve Hanoi tower task on it,to calculate orbit of
satellite,control food-making mashines,etc.(it really have call by
reference!).

Almost any simple realtime control task can be solved (when simplified)
with set of calculators and some help from hardware.
Because there is no need to make flexible programs  with many user-set
options (when someone want to change something,it's simpler to reprogram
calculator from another card:max. 90 steps).

**

About metro("underground"): i don't know why safety so strongly depend
to programming here.Let's use simply hardware blocking(and it's very
simply to design it):when one train are on line,another train phisically
can't go this line(by hardware,on brakes that will set special swiches
on train,and will phisically make lower pressure in brakes system ).

When one train entering >- there is inpossible for another train to be
near it. WHY WE NEED FLEXIBLE PROGRAMS for safety..What,all old
technologies of solving tasks in hardware are lost?Or it's now are "too
expensive"?

Software can be used to control trains,but software should be blocked by
hardware when situation are dangerous.
As in old days when it's controlled by human if all ok, and by hardware
in dangerous situations,except that we SHOULD replace ONLY human by
software,and shouldn't replace hardware by soft even if it's "cheap".

Soft are flexible.Hardware are not. Safety shouldn't be flexible!,

but safety in soft are soft safety...

> 
> [snip]
> 
> > First, I DO NOT want to be a manager, too much bullshit and not enough
> > actual knowledge...pen pushing...no way!
> 
> This I fully understand. But when browsing the English job ads, I have
> noticed that there is a wage leap between an engineer and a
> manager. This is not the case here, where the transition is more
> gradual.
> 
> >
> > Secondly, there are jobs that pay that much and more, they're just don't
> > seem to be in this side of the industry.
> >
> > Thirdly, I really think that that kind of sum is reasonable for a software
> > developer, especially living in London. Nobody can expect to live on
> > anything less than бё35,000 in London, it's just a joke.
> >
> > Luke.
> 
> Right again. I even think that 35K GPB is in the "good end" of the
> scale. And London is so terribly expensive to live in....
> 
> - Mark