From: bruno@athena.mcrcim.mcgill.edu (Bruno Hall)
Newsgroups: comp.unix.sys5.r4
Subject: Re: Dell issue 2.2 video
Date: 7 Nov 92 01:52:55 GMT
Organization: McGill University Broom Closet

peet@locus.com (J. David Peet) writes:
> I (Bruno Hall) wrote:
>>
>>I just got myself an ATI Graphics Ultra, and am mostly pleased with
>>it.  Under Dell 2.2, running Xmach at 1024x768x256, on a (very non-Dell :-)
>>486-33, I'm getting 68,000 Xstones.  It's *great*.
>>
>>BUT I can't seem to make a native VGA DOS image under Merge.  The
>>screen just blanks out, and the thing sits there.  What this means is
>>that I can't access any of the non-standard VGA modes under DOS.  Same
>>story on another machine (different hadrware brand).
>>
>>Has anyone managed to do this with a Graphics Ultra?
>>
>>Naturally, neither Dell nor Locus answer my mail on this topic, which
>>seems strange, particulary since this card is actually supported
>>by Dell, and is a name-brand item to boot. 
>
>Please, I did answer your mail!  My e-mail answer got damaged, and earlier
>today I got e-mail from you in which you stated that you had received
>a screwed up e-mail answer from me.  I was fully intending to try again
>tonight after I finished my regular tasks.  Please give us a little time to
>reply before flaming.  (What if I was on vacation or sick, or was somehow
>prevented from using e-mail?  

Yes, I hadn't thought of that, but then I had also seen posts from you
to the net both before and after I had sent you mail (and received a
munged response ;-).

>A few weeks ago our e-mail and net-news
>connection machine completely died (probably taking a few messages down with
>it), and took a day or so to replace it and get e-mail working again, and
>more than a few days to get news flowing again.)

OK OK, I agree -- I over-reacted.  Mea culpa.

>My reply is this:  Making "native" VGA DOS images only works for a few
>VGA cards.  This is a known restriction.  In the future, it is intended
>that more cards will be made to work, most likely involving special
>code for each new card.

Sounds like a Good Thing.

>Making "native" (a.k.a. on-card-ROM) images is an inherently dangerous
>thing to do (e.g. it can lock up the machine), but if it the image file
>get made, then it is safe to use.  Making "standard" VGA images is
>inherently SAFE, so that is the default one that is made and used.

It's strange.  I use a 'mkimg native vga d .', and the system gets the
copy of the ROM just fine, but it craps out (informs me that it's
making the VGA image, doesn't seek A:, changes video modes, blanks the
screen, and then stops)  when trying to make the DOS image (none is
created).  It doesn't take the system down, however; after switching to a vt
and back, I can kill it.

It's really a pity; the Graphics Ultra is really an excellent card for X. 

>The reason it is dangerous is not due to a "bug", but due to the fact that
>for the boot code in most VGA ROMs to work, we must give it more control
>over the real machine than is normally done.  Thus if the boot time code
>has problems because it is trying to do something that just cannot be
>supported with the current version of Merge, it can hang the machine.
>In several cases I know, VGA ROM boot code plays with the system timer,
>which also controls the RAM refresh.  Having the RAM refresh turned off
>is a very fast way to hang your machine.

So I guess I'm also in the market for SVR4.3 and the new-and-improved
Merge.  :-)

I just hope that Dell doesn't go Solaris before releasing a 4.3...

Bruno
-- 
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
Bruno Hall  |  VE2HUM  |  bruno@mcrcim.mcgill.edu         
McGill Research Centre for Intelligent Machines - Controls Group
New systems generate new problems -- Join the Flat Earth Society.
Newsgroups: comp.unix.sys5.r4