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- Newsgroups: comp.unix.sys5.r4
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!orchard.la.locus.com!prodnet.la.locus.com!peet
- From: peet@locus.com (J. David Peet)
- Subject: Re: Dell issue 2.2 video
- Message-ID: <1992Nov06.035606.0617081@locus.com>
- Organization: Locus Computing Corp, Los Angeles
- References: <1992Oct30.174037.18286@isc-br.isc-br.com> <1311@kepler1.rentec.com> <1992Nov5.071707.17297@thunder.mcrcim.mcgill.edu>
- Date: Fri, 06 Nov 1992 03:56:06 GMT
- Lines: 55
-
- In article <1992Nov5.071707.17297@thunder.mcrcim.mcgill.edu> bruno@athena.mcrcim.mcgill.edu (Bruno Hall) writes:
- >
- >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? 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.)
-
- 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.
-
- 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.
-
- 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.
-
- ---------------------------------------------------------------------
- David Peet Internet: peet@locus.com UUCP:...!uunet!lcc!peet
- Locus Computing Corporation, 9800 La Cienega Blvd. Inglewood, CA 90301
- Fax:(310)670-2980 Voice:(310)670-6500
- ---------------------------------------------------------------------
- Disclaimer: Normally my statements are my own, and not do not
- necessarily reflect those of Locus, but maybe this time they do,
- but then again, maybe not.
- ---------------------------------------------------------------------
-