Re: Ada Tutor Web Site Shutting Down

[Rugxulo <rugxulo@gmail.com>]

Hi,

On May 11, 7:45 pm, "Randy Brukardt" <ra...@rrsoftware.com> wrote:
> "Rugxulo" <rugx...@gmail.com> wrote in message
>
> news:291504a4-ec55-45f1-bf7f-13078bf71c3e@m10g2000yqd.googlegroups.com...
>
> >On May 5, 4:12 pm, "Randy Brukardt" <ra...@rrsoftware.com> wrote:
>
> >> Better, dunno. Janus/Ada 95 (32-bit only) would be updated if anyone
> >> wanted
> >> it, but no one has asked. (It's still in our pricelists.)
> >Updated how?
>
> Just recompiled and tested. It might need some runtime updates, but probably
> not a lot.

What for? Improvements or just to remove the bitrot?

> All of our Ada 95/2005/2012 technology is from a common codebase,
> so building the DOS version just means selecting the right configuration and
> recompiling. (And lots of testing and probably a bit of debugging.)

Ah, testing, the biggest time waster. Luckily, Ada has a public test
suite.

> The biggest problem with it is that the DOS extender we used didn't work
> with NT and afterwards. (It actually works precisely once, then you have to
> reboot before it will work again. Not very practical.)

Was it a special homebrew one or one of the popular ones licensed?
(What brand name?) Well, either way, I'm not surprised. Half the time
the extenders were buggy, but the other half was due to XP limitations
and bugs. (BTW, I assume you meant close/reopen the DOS window, but if
you meant reboot the computer/OS, that's worse! Ugh.)

> > Well, I'm not a
> > customer (and don't know Ada), so I guess that rules me out.  ;-)
> > I'd assume it's "good enough" for the few that use DOS commercially
> > these days. (I assume you probably are more geared towards businesses
> > than home users.)
>
> I don't think we have any DOS customers anymore; they've all moved to
> Windows console mode or to other OSes.

If NT support is buggy, and since XP has been ubiquitous since 2001,
I'm not too surprised. Then again, DOS isn't cool anymore, and people
want (native support for) Unicode, 64-bit, GUIs, Win32 API
(multimedia), etc.

> >> But a better question is why would you want to use a new compiler?
>
> >Why not?  :-)  No, seriously, I was only responding to the OP's claim
> >that Ada95 is obsolete and that his tutorial was in DOS (hence, old)
> >and needed to be updated. I don't even know what compiler he used for
> >it originally.
>
> If I remember right, his tutorial uses a DOS display program. That looked
> old when it was new. ;-)

Well, I blindly assumed he meant some of the code itself was DOS
specific, but who knows, I haven't checked (probably should).

> >> Is there anything inportant that you can do in DOS that you can't do
> >> in a Windows console program or a standard Linux program?
>
> >Sure, run in DOS!  :-))
>
> >(self-modifying code? direct hardware access? run in less than 10 MB
> >of RAM? call the BIOS?)
>
> Self-modifying code: Not with Janus/Ada (no self-modifying code there). We
> wanted it to be reproducible and somewhat secure.

I don't blame you, but people do it! (Of course new cpus run it very
slowly, so it's not recommended anyways, assuming the OS even allows
it!)

> Direct hardware access - I suppose, but is that an advantage?

Only if you need it (some do, most don't). DOS doesn't really support
graphics in the API (unless you count the BIOS or VBE), so you have to
do stuff yourself. Sound support is the real killer (esp. with non-SB
cards these days)!

> Or a security nightmare waiting to happen? Same with "call the BIOS".

People always find a way to breach security anyways. But yeah, DOS has
pretty much none anyways, always "root".  :-)

> Run in less than 10 MB of RAM - I think
> there are Linux flavors that can do that. The Ada programs are pretty small
> for any of the OSes (so that's about the OS footprint).

Most Linuxes aren't geared towards low RAM, esp. nowadays (2.6
kernel). The lightweight ones usually only target 128 MB on up. So I
kinda disagree that Linux can fill that niche (though it doesn't
matter too much these days with tons of RAM, it's just frustrating
when the OS hogs so much, we always seem to need more and more). 128
MB just doesn't cut it these days (I tried!).

> It was pretty much impossible to do anything interesting without doing
> something DOS specific. That's actually true of pretty much every OS target,
> simply because of the different nature of file names on each platform.

If you used old Allegro (or if SDL was supported on DOS), it would be
okay. At least, I assume that's what "interesting" means. (Some people
like purely academic things like calculations, compilers, etc. But
most just want flashy games or GUIs or whatnot.)

> >> I needed to dig up a 1985 version of Janus/Ada for someone. The cool
> >> thing
> >> was that I tried running it to make sure I'd copied it uncorrupted [an
> >> issue
> >> because it copied from 25 year old floppies], and it worked fine
>
> >Yes, that's the ideal, software that still runs for many years in the
> >future. The DPMI standard helped that a lot. For sure, DOS lived a
> >long, long time.
>
> I think 1985 was well before DPMI, and probably was before expanded and
> extended memory, too. This probably was a basic 640K compiler (I don't think
> we even had 640K in our machines at the time - our original IBM PC/XT
> started with 256K, and I think the Seattle Computer 10 MHZ 8086 [much faster
> than the PC] had about that as well).

Right, sorry, I knew that. Though there were 286 extenders by then,
but the 386 didn't even come out until 1986 or so (and took a while to
get adopted). Real EMS existed, of course, as did XMS, but it was
fairly rare. Even in 1994, my new PC only had 4 MB of RAM! My, how
times have changed.  :-O

But yeah, VCPI (386+) was 1986, DPMI (286 or 386) was 1990. And I hear
that SCP-8086 could use the full 1 MB (unlike IBM's 640 kb). I assume
this means yours was a multi-pass compiler (a la Wirth's old M2M /
Modula-2). But maybe not, perhaps you crammed a lot into "256K" (Ada83
only probably made it easier).

> >Unfortunately, Windows has gone downhill (in DOS support) since XP,
>
> You could have just left out the parenthetical remark, and you still would
> have been right. ;-)

More or less, yes. I know MS thinks XP is old and wants to deprecate
it, but it seemed fine to me. But I'm sure some fringes had various
complaints about it that only Vista or 7 solved. I'm not Windows-y
enough to know, honestly. (But I do think they charged too much for
Vista -> 7 ["minor"] upgrade.)

> >and 64-bit completely kills it. (XP Mode is only for business
> >editions, not home users.) You'll have to use DOSBox or VirtualBox
> >(preferably with VT-X) or else switch to Linux for DOSEMU. (Well, you
> >could run FreeDOS natively, but I doubt most will consider that.)
>
> That's one of the reasons I'm not moving most of my work to Windows 7
> anytime soon. I still use a number of DOS programs regularly, including a
> circa 1986 programming editor.

I'm surprised, honestly, most people spit on the idea of (still) using
DOS software. But not me!  ;-)   Windows 7 32-bit probably (somewhat)
works for DOS, as I know Vista 32-bit barely did (some bugs, DPMI
registry hack needed, no full screen gfx).

Though I wonder at using such an old editor, but I know people like
what they like, so I can't complain. (Text editors are a dime a dozen
but none do everything, not even Emacs or VIM. Check out http://www.texteditors.org
sometime for a laugh.)