Subject: Linux-Misc Digest #809
From: Digestifier <Linux-Misc-Request@senator-bedfellow.MIT.EDU>
To: Linux-Misc@senator-bedfellow.MIT.EDU
Reply-To: Linux-Misc@senator-bedfellow.MIT.EDU
Date:     Mon, 14 Mar 94 01:13:13 EST

Linux-Misc Digest #809, Volume #1                Mon, 14 Mar 94 01:13:13 EST

Contents:
  Re: I'm developing UMSDOS Linux Pkg. (Jim Morris)
  Re: BSD vs. Linux (David Holland)
  Re: FAQ: Cut & Paste from vir (Robert Millner)
  Re: tcp wrapper (Robert Millner)
  Seeking anecdotes about Linux supported sound cards + tape backups (James D. Levine)
  Re: xconsole doesn't work (James D. Levine)
  Re: Cyrix 486DLC/40 Compatibility with Linux (Patrick Brewer)
  Re: Linux on 680x0:  Is it Mac or Amiga? (Alan Braggins)
  Upgradability? (RYAN HUNG)
  Re: broken crond ? (Jeremy Bettis)
  Re: DOOM for X (Mark K Vallevand)
  Re: libm.so.4.5.21 in /usr/lib ?? (David E. Filip)
  Re: "Reverse-engineering" (Ian Jackson)
  Re: *** DON'T READ THIS BEFORE POSTING *** (Ian Jackson)
  VideoCards (Werner.Depoorter)
  Re: Don't want to make floppys! (Henrik Lund)
  Re: Multiple screen feature in Linux? (Nickolay Saukh)
  Re: Sparc vs. 486/Pentium [WAS:Re: Mail Order Linux Workstation Vendors] (Philip Brown)
  Re: DOOM for X (Amancio Hasty Jr)

----------------------------------------------------------------------------

Crossposted-To: comp.os.linux.development
From: jmorris@darkstar.rastek.com (Jim Morris)
Subject: Re: I'm developing UMSDOS Linux Pkg.
Date: Thu, 10 Mar 1994 17:47:04 GMT


I think Patrick has already done what you propose, with the recent
Slackware 1.1.2 UMSDOS disk set.  By using the UMSDOS Boot/Root disk combo,
as well as a couple of other UMSDOS disks, you can install the Linux Slackware
distibution (as much or as little as you like of it) onto an MS-DOS formatted
disk.

I believe that he requires you to have 8MB or RAM to install with UMSDOS,
because if your hard disk is formatted for DOS, odds are you are not going to
be able to create a swap partition for the install process to use.

I also think that Patrick's notes on Slackware 1.1.2 state that the smallest
UMSDOS installation (UMSDOS and A diskette series) is around 12MB of hard
disk space.

Jim Morris
(jmorris@rastek.com)

------------------------------

Crossposted-To: comp.unix.bsd
Subject: Re: BSD vs. Linux
From: dholland@husc7.harvard.edu (David Holland)
Date: 13 Mar 94 16:39:25


nate@bsd.coe.montana.edu's message of 11 Mar 1994 18:36:07 GMT said:

 > >Don't forget that a 15 year advantage also means 15 years of
 > >accumulated cruft.
 > 
 > *WRONG*

Yes, it does. The Ultrix kernel (for example) has all sorts of cruft
in it associated with supporting obsolete terminal hardware and stuff
like that. Just for example. Are you going to convince me that BSD
doesn't suffer from the same sorts of problems? Re(?)-read _The
Mythical Man-Month_. All large systems eventually end up with lots of
unnecessary junk.

 > >NetBSD (and the other 386 BSDs) require more system
 > >than Linux does.
 > 
 > *WRONG*
 >
 > [some stuff about disk space deleted]

Disk space isn't the issue. When I went looking around last summer, I
was told/found out from FAQs that Linux ran quite happily on a 386SX
with 4 megs of RAM, whereas *BSD didn't. Considering that I *have* a
386SX with 4 megs of RAM, this was an important issue.

Maybe I got wrong information; in that case somebody ought to fix up
the BSD FAQs.

--
   - David A. Holland          | "The right to be heard does not automatically
     dholland@husc.harvard.edu |  include the right to be taken seriously."
   -  -         -         -       -         -  -    -     -        -
 This message shall NOT be quoted or copied out of the electronic medium
 in which it originated without explicit permission from the author. 

------------------------------

From: millner@sps1.phys.vt.edu (Robert Millner)
Subject: Re: FAQ: Cut & Paste from vir
Date: 12 Mar 1994 07:12:29 GMT

Rick Emerson (rick.emerson@satalink.com) wrote:
:  @SUBJECT:FAQ: Cut & Paste from virtual terminal                      N
: I know the answer must be in a FAQ somewhere but darned if I can find
: it!  How do I cut and paste from a virtual (*not* X!!!) terminal?
: Replies to rick@ssg.com, flames to /dev/null.

: Rick
:   
: ...
:  * ATP/Linux 1.42 * The only argument with the wind is to put on a coat.

        In your rc script somewhere, place a line calling the selection
program.  In ours:         

echo -e "Starting mouse selection server.\r"
/usr/bin/selection &

Then copy and paste can be activated by hitting the left button once.  That
should activate the mouse cursor on the screen.  The right will paste.
        Rob
 

--
millner@sps1.phys.vt.edu
millner@vt.edu
millner@cebaf.gov
Finger millner@sps1.phys.vt.edu for more info
        and for PGP public key.


------------------------------

From: millner@sps1.phys.vt.edu (Robert Millner)
Subject: Re: tcp wrapper
Date: 12 Mar 1994 07:15:42 GMT

Brad Cain (brad@bach.udel.edu) wrote:
: Has anyone ported a tcp wrapper to linux??



: -- 
: ****************************************************************************
: brad@ravel.udel.edu            Brad Cain                             N3NAF
: cain@snow-white.ee.udel.edu    University of Delaware Electrical Engineering

        Yes.  tcpd.  You should be able to find it on either sunsite or
        tsx-11.   Nuff said.
                R


--
millner@sps1.phys.vt.edu
millner@vt.edu
millner@cebaf.gov
Finger millner@sps1.phys.vt.edu for more info
        and for PGP public key.


------------------------------

From: jdl@netcom.com (James D. Levine)
Subject: Seeking anecdotes about Linux supported sound cards + tape backups
Date: Sun, 13 Mar 1994 22:07:24 GMT


I'm in the market presently for a sound card and a tape backup unit.  
Having changed jobs, I no longer have Computer Select handy, and I'm too 
lazy to look for reviews, so I'm hoping some of you out there will choose 
to offer you experiences.  I've read various documents and bits of kernel 
patches on sunsite, but I still don't have enough of a warm+fuzzy feeling 
to go make a purchase.

For the sound card, my desire is first to enjoy my new copy of Doom 
fully, then soon after Linux audio, PC multimedia.  Later than that I 
want to do some musical composition, and maybe text-to-speech work.

Tell me if I'm wrong, but it seems the main players are Sound Blaster and 
Pro Audio.  Which narrows it down to about eight different models.  
Sound Blaster has to be the most confusing product line I've seen in a 
long, long time.  I've walked into my local electronics store a number of 
times with the intention of purchasing a sound card, only to leave all 
glassy-eyed and confused.  Help, please!

For the tape backup unit, I'm want something that's reliable and cheap, 
and straightforward to use under both Linux and DOS.  Speed would be 
nice, as would compatibility with other tape backup units - but that's 
less important.

Any takers?  Your comments will be much appreciated.

James


------------------------------

From: jdl@netcom.com (James D. Levine)
Subject: Re: xconsole doesn't work
Date: Sun, 13 Mar 1994 22:11:32 GMT

I have the same problem with xconsole.  After checking permissions on 
/dev/console, I gave up.  The easy workaround is-

# xterm -C -name "Console" &

James


: Mark Fernyhough (ferny@pc64.maths.bris.ac.uk) wrote: : [ Article 
crossposted from comp.os.linux.help ] : [ Author was Mark Fernyhough ]
: [ Posted on Sat, 12 Mar 1994 17:18:09 GMT ]

: I can't get xconsole to work at all. All the messages go to the virtual
: console were i started X. 
: Cany anyone help?

: Thanks in advance
: Mark


------------------------------

From: noble@garfield.catt.ncsu.edu (Patrick Brewer)
Subject: Re: Cyrix 486DLC/40 Compatibility with Linux
Date: Fri, 11 Mar 1994 19:11:37 GMT


        I have been running Linux on a Cyrix 486 for 3 months now with 
out much problem.  But I have patch level 14 ( I believe.)  What ever 
was latest in Dec. 93.  Does this mean that newer versions of Linux 
=======================================================================
Patrick W. Brewer           CATT Alumni  
noble@catt.ncsu.edu

------------------------------

From: armb@setanta.demon.co.uk (Alan Braggins)
Subject: Re: Linux on 680x0:  Is it Mac or Amiga?
Date: Fri, 11 Mar 1994 15:29:53 GMT

In article <2lop7b$c1i@ucsbuxb.ucsb.edu> uoutrigg@mcl.ucsb.edu (Joel Rising) writes:
>   I saw it on tsx-11.mit.edu, pub/Linux/680x0.  It seems from the
>   readme's that it's just for Amiga, but then again it didn't seem
>   at all clear.  Does anyone know if it works on Mac?

From a recent posting by Hamish Macdonald - there is no such thing as
"Amiga Linux", but Linux/68k currently only runs on Amigas...  There
is an empty directory waiting for Apple support (and another for Atari).

>   But he won't touch anything without a little apple on it.  Should I hold
>   my breath?
Well, even the Amiga version is only alpha code.

>  Should I get an iron-on decal?
or a new boss...
--
Alan Braggins  armb@setanta.demon.co.uk  abraggins@cix.compulink.co.uk
"Any technology distinguishable from magic is insufficiently advanced"

------------------------------

From: rhung@physics.ubc.ca (RYAN HUNG)
Subject: Upgradability?
Date: 12 Mar 1994 02:43:01 GMT

I'm waiting for the release 1.0 of the Linux kernel before I install
Linux.  However, I've been wondering: considering the rapid rate of change
in Linux, how easy is upgrading?  Say, for example, there were a kernel
upgrade.  Do distributions usually provide upgrade packages that can run
quick and easy?  Or is a lot of hacking necessary?

                                                        Ryan.
--
     |      |The Enterprise going into warp?  | rhung@physics.ubc.ca
   --O-- <--|Or a ship blowing up? Or a star? |  or (XOR!)
     |      |...Or just 2 |'s, 4 -'s, & an O? | rwhung@netinfo.ubc.ca

------------------------------

From: jbettis@cse.unl.edu (Jeremy Bettis)
Subject: Re: broken crond ?
Date: 13 Mar 1994 22:59:50 GMT

cummings@stingray.speedway.net writes:
>James Morris (jmorris@mu.apana.org.au) wrote:
>: The crond program on my system is acting strangely..
>: When I boot Linux, it sets off all of the crontabs - even
>: ones that are not due to be executed at the time.
>: The base system is Slackware 1.1.1 (Linux pl.14).

>Same base system here.
>Yes, I have the same, though it worked fine until I put up ALPHA 1.0, then
>it does what yours is doing.  Kinda bogs the machine down.  I would love to
>see some advice here, I plan to get the source to crond and recompile and
>see if it helps, will post results if it works.

Yes, getting the new cron should fix it, but this should make the problem go
away.

In /etc/rc (i assume) crond is started up, and also the system clock is set
from the CMOS clock.  Make sure that the clock is set first! before crond is
started.  What is happining is that crond notices that the time changed and
tries to catch up by executing all the things which happened between the old
time and the new time.  So when you set the clock, crond has several years of
catching up to do. (probably, I assume that your date is years off before the
clock is set)
--
Jeremy Bettis   -*-   Jerbo Jehoshaphat   -*-   University of Nebraska
INET:   jbettis@cse.unl.edu             "Those who stand in the middle of the
UUCP:   jerbo@tddi.UUCP                  road are often hit by passing cars."
Running Linux .99p14 Free Unix for i386/i486/Pentium machines. Ask me how.

------------------------------

Crossposted-To: comp.os.386bsd.apps
From: markus@rsvl.unisys.com (Mark K Vallevand)
Subject: Re: DOOM for X
Date: Fri, 11 Mar 1994 17:42:36 GMT

In article <glen.763349922@paladine> glen@paladine.ece.jcu.edu.au (Glen Harris) writes:

>In <2lm9ih$6s5@godot.cc.duq.edu> mcquill@next.duq.edu (Tod McQuillin) writes:
>>Amancio, what effect, if any, do you think the shared memory extentions of X
>>have on graphics performance?

>  What it means is that a bitmap in memory is mapped directly over the
>screen, so an access to the array is an access to the screen.  After the
>mapping is set up, there's no calls to X for the graphics.  In effect,
>it's exactly as if you were in dos, but there's no 64Kb segment switching
>as the system does this transparently.  *I* don't know how page flipping 
>is done, maybe there's a X call to do this, or a fast memcpy during the
>refresh?  Inquiring minds.......

No, no, no.  The X shared memory extension simply gives the X app and X server 
shared access to a piece of memory so that they can exchange data quickly.  
Instead of sending a huge message through, a tiny message is sent with a 
reference to the shared memory that has the huge chunk of data.  It's not 
exactly as it is in DOS.  Its not that close to what it is in DOS.  

Get a book about X programming.  Read about images and pixmaps.  If you can 
understand that, the shared memory extension is just a way to excelerate image 
and pixmap operations.


Regards.
Mark K Vallevand    Unisys Corp  Roseville, Minnesota    markus@rsvl.unisys.com
Mail Station 4313, POBox 65942, St Paul, MN 55164   612-635-7880

On the Information SuperHighway, I'm the guy with a hat driving 50 in the fast 
lane with my blinker on and my seatbelt hanging out the door making sparks.

------------------------------

Crossposted-To: comp.os.linux.admin
From: dfilip@colornet.com (David E. Filip)
Subject: Re: libm.so.4.5.21 in /usr/lib ??
Date: Fri, 11 Mar 1994 04:38:12 GMT

Helmut Geyer (geyer@polyhymnia.iwr.uni-heidelberg.de) wrote:
: :>    I belive someone made this suggestion earier, but why don't we
: :>have a LIBPATH variable or have it automaticaly check /lib then /usr/lib
: :>then /usr/X386/lib? Would it break all programs in existance or be impossible
: :>to implement?

: It _IS_ implemented. ld.so does just this. The problem here is due to 
:       (i)  old binaries (which do not use ld.so
:       (ii) binaries that need libm and might be uses before /usr is mounted.

I am comming in at the end of this thread ... however, I am having difficulty
with libm, so I am hoping that perhaps this thread MIGHT be telling me what
is going wrong ... but I'm just not sure what !

I am trying to compile some X sample code (specifically, the sspkg stuff
under xview from the Slackware distribution) and I am told that ld cannot
find libm (specifically, ld: no such file or directory libm). Now, does
that mean that for some reason I am running ld and not ld.so, which is
not looking for shared libraries ? Or, is it for some reason not looking
in /lib (which is where libm.so.4 lives) and I need to move it to /usr/lib ?

According to the man page for ld.so, it does implictly look in both /lib and
/usr/lib, again, unless for some reason it thinks that it needs a static
lib (and I do NOT have a libm.a).

Any help would be appreciated. Yes, I am a newbie here, and will need to build
some rather large X-based clients in the VERY near future (like next week) and
would appreciate any help I can get.

Regards,

Dave.


------------------------------

From: iwj10@cus.cam.ac.uk (Ian Jackson)
Subject: Re: "Reverse-engineering"
Date: Sun, 13 Mar 1994 20:46:56 GMT

In article <ag129.551.2D7F667C@ucs.cam.ac.uk>,
Alasdair Grant <ag129@ucs.cam.ac.uk> wrote:
>>        Another suggestion made by Brooks is that programmers be
>>given a "playpen" area to fool with their code before its sent to
>>the integrators. The size of the "playpen" for any given FSF project
>>is astronomical compared to the tiny little development labs of IBM.
>
>In size but not variety.  The fact that Linux doesn't support MCA, and
>doesn't talk AppleTalk or NetWare, just shows how limited the scope of
>most peoples' "play" really is.

The reason Linux doesn't run support MCA or NetWare is in each case
difficulty in obtaining relevant information.  I expect that the same
is true of AppleTalk, though a lack of people wanting the facility may
well have some impact there.

>  IBM (or Microsoft or Novell) don't
>test things on a few thousand Dell 386s; they get lots of different
>stuff, plug it all together, and fix the bits that break.

This is exactly what is being done with Linux.

For starters, Linux users can't afford Dells :-).  Seriously, Linux
*is* being used on a very large range of hardware, and it constantly
amazes me how little it breaks (especially considering the brain
damage in the ISA architecture).

>>Statistically, once the initial work on a project is done, the
>>fastest progress is made by flying through the spiral as fast as
>>manpower allows. The inference is obvious.
>
>So when can we expect Linux v1.0?

No more than two months.  An alpha version of 1.0 has been out for a
week now; my best guess would be another two weeks.

-- 
Ian Jackson, at home  <ijackson@nyx.cs.du.edu> or <iwj10@cus.cam.ac.uk>
PGP2 public key available on server.  Urgent email: <iwj10@phx.cam.ac.uk>
2 Lexington Close, Cambridge, CB4 3LS, England;  phone: +44 223 64238

------------------------------

From: iwj10@cus.cam.ac.uk (Ian Jackson)
Subject: Re: *** DON'T READ THIS BEFORE POSTING ***
Date: Sun, 13 Mar 1994 18:48:05 GMT

In article <2lp6qt$m5c@crl.crl.com>, Bill Hogan <bhogan@crl.com> wrote:
>  If you have a question, just ask it!

No, please don't.  Read the FAQ and HOWTOs first.

Posting your question without reading the FAQ and HOWTOs is very rude.
Doing so in this newsgroup is even ruder.

Bill Hogan: please go and read the introductory documents in
 rtfm.mit.edu:/pub/usenet/news.announce.newusers

>  (A great scientist was once asked if he had found the answer. "Answers
>are relatively easy", said the Professor, "finding the right question,
>that's the hard part.")

I fail to see the relevance of this paragraph.

-- 
Ian Jackson, at home  <ijackson@nyx.cs.du.edu> or <iwj10@cus.cam.ac.uk>
PGP2 public key available on server.  Urgent email: <iwj10@phx.cam.ac.uk>
2 Lexington Close, Cambridge, CB4 3LS, England;  phone: +44 223 64238

------------------------------

From: depoort@uia.ac.be (Werner.Depoorter)
Subject: VideoCards
Date: Sun, 13 Mar 1994 23:47:02 GMT


Hello,

In my search for a new videocard, I have to decide between two possible 
cards.  Are there any people who can advice me?

At this moment most of the time I use X under Linux (99.9% X,
0.1% MS-windows). This may be important because the not all cards are 
fully supported by this kind of software.

The two cards (ISA-cards, I don't have a local bus):
- STB Powergraph X-24 (S3/801, 1Mb Dram, price 8500 BEF)
- ATI Graphics Ultra + (Mach 32, 2Mb Vram, price 13500 BEF)

I have several questions:
- Is there a noticable difference in speed?
- Can the ATI handel the 1280x1024 resolution (and by which refresh rate)?
- Are there any problem with the 2Mb from the ATI (My PC has 20Mb RAM)
  (Some people said this can give some trouble if you really want to 
   use the 2Mb from the Videocard)
- Is there a X-server who can handle more than 256 colors?

Werner.

------------------------------

From: lund@diku.dk (Henrik Lund)
Subject: Re: Don't want to make floppys!
Date: Thu, 10 Mar 1994 10:45:45 GMT

grante@hydro.rosemount.com (Grant Edwards) writes:

>I used the Yggdrasil CD for the first couple machines upon which I
>installed Linux. This time, the machine doesn't have a SCSI
>controller.
You know Yggdrasil supports other NON-SCSI CDROM drives.
Much bigger problem if system hasn't got CDROM drive :-)

>So, I decided to install a base system + network from floppies, then
>install everything else via NFS.  My first choice was debian -- but it
>won't install packages from a fs that's already mounted. As far as I
>can tell, you have to have floppy disks.  I've got all of the packages
>I want already on the Linux machine's hard disk, but I can't install
>them from there, and I refuse to make a bunch of floppies containing
>stuff that's already on the hard disk!

If you just wan't to install a copy of another harddisk which is NFS mounted
then copy it. If you have Yggdrasil on one machine then nfs mount the new
harddisk and reinstall yggdrasil (using the new harddisk which is NFS mounted,
as you did when you installed on the local harddisk). I guess the job would be
something like. 

        Reboot yggdrasil from the bootdisk/cdrom (you might be able to do it 
from harddisk ?)
        Then NFS mount the "new non-local" harddisk and begin the install.

>Next, I thought I would try Slackware.  According to the README files
>I have to make a bunch of floppy disks with MS-DOS file systems from
>which to install the system.  Yikes!  Why bring MS-DOS into the
>picture?

Because the MSDOS filesystem structure is so simple and therefore universally
available in anything from MAC/PC's to SUN, NeXT, ....
Downloading and writing to msdos floppies can be done on just about any site.

Some versions of mount doesn't care and will let you use the filesystem of 
your choice. Just do "make minix filesystem" on your sun, might have to call
hotline for the name of the executable, 'mkfs' on some system.  
 
>A suggestion to people working on installtion procedures for Linux
>distributions:

You have the right to edit installation scripts to suit your needs !
 
>Let people install additional packages from mounted file systems!!!
I'm sure that you haven't tried all distributions and therefore i say:
        DON'T blame distributions that you haven't tried, make one yourself
and I will blame YOU if it doesn't suit MY silly setup, or if it doesn't 
include the packages I need in the version with the facilities that I NEED
and if I don't like the way you named your distribution or the default hostname
or .. or ...

I have an old SLS (1.03 I think) which ask if I wan't to install from
the SLS cdrom, floppy, NFS mounted filesystem !, harddisk etc.
If SLS has this anybody critizing SLS should have it or stop whining :-)
(I think SLS was great, if there hadn't been any SLS distribution I wouldn't
have begun using Linux)   

Makers of distributions do a great job tell them politely how they can make 
them better instead of bitching about them.
The same goes for "bug reports", don't scream BUGS , because YOU didn't read
the READ/FAQ.

>--
>Grant Edwards                                 |Yow!  Pardon me, but do you
>Rosemount Inc.                                |know what it means to be
>                                              |TRULY ONE with your BOOTH!
>grante@rosemount.com                          |

Just my two DKR. Hope Grant succeeds in his quest on installing via NFS.
 
-- 
Henrik Lund  LINUX: fast, free, flexible PC-UN*X  X, gcc etc on 386DX/25MHz
lund@diku.dk Computer Science Student at University of Copenhagen, DIKU
All opinions are mine, but you may redistribute them according to
Gnu General Public License 2. Messy-DOS/drugs just say NO, NO, NO, NO !

------------------------------

From: nms@KremlSun.ussr.eu.net (Nickolay Saukh)
Subject: Re: Multiple screen feature in Linux?
Date: Sat, 12 Mar 1994 06:31:16 GMT

Ron Smits (ron@draconia.hacktic.nl) wrote:

> It is exactly the same in Linux, You must start up gettys on the different
> virtual consoles who are named tty[1-8]. You can then switch between
> them with ALT-F[1-8].

But if I want vtlmgr (from svr4) functionality? I am lazy enough
to pass login/password procedure for each screen while been the
only user around ;-)

------------------------------

From: philb@cats.ucsc.edu (Philip Brown)
Crossposted-To: comp.unix.pc-clone.32bit
Subject: Re: Sparc vs. 486/Pentium [WAS:Re: Mail Order Linux Workstation Vendors]
Date: 12 Mar 1994 07:39:53 GMT


In <JROZES.94Mar11105226@allegro.cs.tufts.edu> jrozes@allegro.cs.tufts.edu (J Rozes) writes:

>One thing you should know: Sun is not exactly know for it's I/O performance.
>I use a SparcClassic with 16megs RAM and it feels much slower than a 486/66
>with the same amount of memory in terms of system load. Despite the 16megs,
>the Sparc swaps like mad, even when not running OpenWindows.


DESPITE the 16 megs? hahahaha... I can only laugh at that.
Solaris requires about 24 megs to run smoothly. 16 megs is a "minimum"
setup. Besides, which, a sparc classic is similar to a "mac classic" in
that it has lots of engineering shortcuts. like a much
smaller-than-normal cache, I hear.

I think solaris x86 would equally crawl on 16 megs of memory on a 486 ?


Can't argue that a 486/PCI is a "bargain", although personally, I'd
recommend a pentium PCI. They're not that much more expensive nowadays.

Don't forget to add decent PCI ethernet cards, isdn boards, and scsi-II
boards for your intell systems either way, thou. How much more $$ is
that? :-)

I personally lke buying used SUN hardware, cause it's solid as a rock.

-- 
 ----------------------------------------------------------------------
Philip Brown, CIS major, UC Santa Cruz
Author of "kdrill", and "xmandel"
Winging my way out of academia soon...
philb@cats.ucsc.edu philb@soda.berkeley.edu

------------------------------

Crossposted-To: comp.os.386bsd.apps
From: hasty@netcom.com (Amancio Hasty Jr)
Subject: Re: DOOM for X
Date: Sat, 12 Mar 1994 08:03:35 GMT

In article <markus.57.00E736E9@rsvl.unisys.com> markus@rsvl.unisys.com (Mark K Vallevand) writes:
>In article <glen.763349922@paladine> glen@paladine.ece.jcu.edu.au (Glen Harris) writes:
>
>>In <2lm9ih$6s5@godot.cc.duq.edu> mcquill@next.duq.edu (Tod McQuillin) writes:
>>>Amancio, what effect, if any, do you think the shared memory extentions of X
>>>have on graphics performance?
>
>>  What it means is that a bitmap in memory is mapped directly over the
>>screen, so an access to the array is an access to the screen.  After the
>>mapping is set up, there's no calls to X for the graphics.  In effect,
>>it's exactly as if you were in dos, but there's no 64Kb segment switching
>>as the system does this transparently.  *I* don't know how page flipping 
>>is done, maybe there's a X call to do this, or a fast memcpy during the
>>refresh?  Inquiring minds.......
>
>No, no, no.  The X shared memory extension simply gives the X app and X server 
>shared access to a piece of memory so that they can exchange data quickly.  
>Instead of sending a huge message through, a tiny message is sent with a 
>reference to the shared memory that has the huge chunk of data.  It's not 
>exactly as it is in DOS.  Its not that close to what it is in DOS.  

The above is correct. 

Well, at least with the S3 801/928,864 we can map the entire cards
video memory into a user space. Linux (whatever version is at ) can
can do this --- if memory does not fail me  XFree86 for linux does this.

There was a limitation on FreeBSD which prevented  us from mapping 
the entire S3's memory. With the latest release of FreeBSD we should
be able to do it also.

It should be interesting to find out if we can make the X server's
video memory shared with a clients space so that an application 
can read or write as fast as it can to the card. In essence
take complete control of the card just like in DOS. Well not quite
because there is the matter of vga commands or s3 graphic commands
to the card that one can't issue from the client unless one gets
ioperm and if one keeps going on this direction there is no need for
the server because  one duplicates the server code. Lets called
this morphing code :)


A different but related solution to the above problem.

When I used to work for touch communications, we implemented a 
terminal server for our OSI stack. -- The OSI stack was one
of those client-server models;however, the architects had a
good enough sense to also specify an api for each level of the
osi stack. So our terminal server became part of our OSI stack
residing at the tranport layer level. With very little effort I also
merged our FTAM server (file server stuff) to our stack to
just measure the performance impact of our IPC mechanism. It was
a lot in our case because we used ASN.1 encoding... This is not
to say that X's IPC is a high overhead rather that one can have 
a server which also has clients in the same process space.

Okay, I will get off my soap box. The ideal situation for us
is if the so called X server could  also provide an interface so
we can access the server's low level graphic functions an exploit
the underlying graphic hardware. Or forget about X and standardize
on a graphic library for graphically demanding applications.

BTW: sgi took the approach of both X and access to the low level
graphics. So an app is capable of accessing the low level graphic
hardware at a very fast speed, while X is well doing slowly its
own thing.

        Hope this inspires someone out there,
        Amancio



-- 
FREE unix, gcc, tcp/ip, X, open-look, interviews, tcl/tk, MIME, midi, sound
at  freebsd.cdrom.com:/pub/FreeBSD
Amancio Hasty,  Consultant |
Home: (415) 495-3046       |  
e-mail hasty@netcom.com    |  ftp-site depository of all my work:    
ahasty@cisco.com           |  sunvis.rtpnc.epa.gov:/pub/386bsd/X

------------------------------


** FOR YOUR REFERENCE **

The service address, to which questions about the list itself and requests
to be added to or deleted from it should be directed, is:

    Internet: Linux-Misc-Request@NEWS-DIGESTS.MIT.EDU

You can send mail to the entire list (and comp.os.linux.misc) via:

    Internet: Linux-Misc@NEWS-DIGESTS.MIT.EDU

Linux may be obtained via one of these FTP sites:
    nic.funet.fi				pub/OS/Linux
    tsx-11.mit.edu				pub/linux
    sunsite.unc.edu				pub/Linux

End of Linux-Misc Digest
******************************
