Newsgroups: comp.sys.ibm.pc.games.action
Path: samba.oit.unc.edu!concert!gatech!howland.reston.ans.net!sol.ctr.columbia.e
From: edlee@chinet.chinet.com (Edward Lee)
Subject: Re: Summary of DOOM Problem Fixes
Message-ID: <CHz6FL.1zD@chinet.chinet.com>
Organization: Chinet - Public Access UNIX
References: <CHyApy.Gs2@chinet.chinet.com> <2eglf0$mb5@usenet.rpi.edu> <JASON.93
Date: Mon, 13 Dec 1993 13:21:20 GMT
Lines: 149

Version 2

Here is a collection of possible fixes reported by various people on the
net for problems that you may be having with running Doom.  Not all of
these fixes may apply to you, and some of them conflict with each other.
If any of these fixes solves your problems with DOOM, then that is all
that matters, right?

GETTING DOOM TO DO SOME UNIMPORTANT THINGS SUCH AS, UM, LET YOU PLAY:
o       You need 4 Megabytes+ of RAM to play, a hard drive, VGA
        graphics, and an 80386 class processor or better.

o       Change the Sound Blaster interrupt to 5 and change the mouse
        interrupt to 3.

o       If your BIOS allows it, set the speed detection explicitly to
        your computer's speed, such as 66 Mhz, instead of using
        automatic speed detection.

o       If you have an AMI BIOS that lets you turn off hidden refresh,
        then turn off hidden refresh.

o       If your computer has a Turbo button, disable secondary cache
        and slow down the computer with the Turbo button before DOOM
        starts up.  At the title screen, where there is a picture of a
        muscular guy wearing a helmet, speed up the computer by
        activating the Turbo button.

o       If your computer has an AMD 80386DX 40 Mhz and a ULSI math
        coprocessor, you might try removing the math coprocessor
        from its socket.  DOOM probably uses fixed-point math for all
        calculations, so the presence of a math coprocessor would
        not speed up DOOM.

o       Remove or comment out all memory managers from your CONFIG.SYS
        file.  This includes EMM386.EXE, QEMM, HIMEM.SYS, etc.  DOOM
        does not need these memory managers.

o       You need a directory on your hard drive called DOOM and
        DOOMDATA on the root level, in case you manually extracted some
        DOOM files and do not have these directories already.

o       You may have problems using OS/2 with the Sound Blaster
        together.  Drop to MSDOS and run DOOM.

o       Use MSDOS v5.0 instead of MSDOS v6.0+.

o       Run DOOM on an uncompressed hard drive or on an uncompressed
        partition.

o       ATI Graphics Ultra & 2.88M floppy controllers might not work with
        DOOM.  A Genoa ET4000 card and regular floppy controller might work
        instead.

o       "Booting the system with at least 2592 K of expanded (yes EXPANDED)
        memory cleaned up everything. A boot without any expanded memory
        managers (all extended), crashed even worse than before."
        pcasey@hmcvax.claremont.edu

o       Do not try any of these fixes, even if you desperately want
        to play DOOM, and try to be patient enough to wait only a
        month or longer before the start-up problems of DOOM on your
        computer system are fixed ... nah

o       In the meantime, if all else fails, dance around your computer
        while singing Christmas carols and hope that the computer is in
        a good mood and will let you play DOOM.  (Why not?  Mood spelled
        backwards is dooM :-)

One person from Hewlett Packard mentioned that DOOM dereferences a NULL
pointer at some point in the game or introduction, and if this true and
if this is the only real major problem, then the solution would have to
be a bug hunt in the DOOM source code or the DOOM operating system source
code by Id programmers, a bug hunt in the DOS4GW Professional code by
Watcom programmers, or perhaps something else.  What dereferencing a NULL
pointer usually means is that the computer is instructed by a program
to look at the first memory location in memory, at address 0, and use
the contents of this memory location as the address of another memory
location in which to write or read data.  This is a common error that
is usually caused by an oversight by a programmer during dynamic memory
allocation.  The effect of dereferencing a NULL pointer depends on what
is located at address 0 and how a computer program uses what is located
at address 0.

The contents of address 0 might be different on slightly different computer
systems.  On IBM PC-compatible computers, the contents of address 0 may
depend on what hardware devices are attached to the computer, or the
contents may change over time during the execution of a computer program
depending on what interrupts occur or what other NULL pointer dereferences
occur.  This might explain why some fast IBM PC-compatible computers
running at 66 Mhz crash with DOOM.  The probability that a NULL pointer
dereference will cause a crash might be small for most people, but a
computer running at 66 Mhz with more frequent interrupts may increase the
probability of a crash within the running time of a program like DOOM.  A
quote in one Unix fortune program states that computers allow us to make
more mistake in a shorter amount of time than ever before, or something to
that effect, and the quote may apply here.  A NULL pointer dereference
may also explain why several different people may have to do their own
unique things, such as modify what software is in memory or modify
the configuration of their peripherals, to get DOOM to work on their
computer systems.

Another possibility is that if you are using a clone of an Intel processor
or coprocessor instead of one actually from Intel, then the clone processor
might not be fully compatible in protected mode, which is the mode that
allows Watcom's DOS4GW to provide a flat, linear address space to programs
that use it, such as DOOM.  Mentioning the brand of CPU or coprocessor
that you use might be revealing if you have a problem to report to Id
Software or Watcom.

GETTING DOOM'S SOUND OR MUSIC TO WORK
o       Change the IRQ of your sound card to something under 9

o       If you are using the GUS card, put the DMXGUS.INI file in your
        DOOM directory.  DMXGUS.INI should be available at an FTP site
        near you.

GETTING ACCEPTABLE SPEED OUT OF DOOM
o       Set the detail of the game to low detail and reduce the size of
        the play screen by pressing the - key on your keyboard.

o       Do not use the mouse or its driver.  Disconnect the mouse
        and/or the mouse card.

o       Do not activate sound or music.

o       If you have a Packard Bell computer that comes with RAMBIOS.SYS
        and EAGLE.COM, install RAMBIOS.SYS as a device in your
        CONFIG.SYS file, such as:

        DEVICE=C:\DOS\RAMBIOS.SYS

        and activate 16-bit VGA with EAGLE.COM in your AUTOEXEC.BAT
        file:

        EAGLE FAST

        This should speed up your video performance.

o       Buy a new computer system or motherboard, preferably one with
        local bus video.

GETTING ACCEPTABLE BRIGHTNESS OUT OF DOOM'S SCREEN COLORS
o       Turn up your monitor's brightness.  That is, if you can't handle
        the darkness (nudge, nudge) and don't want to feel the same kind
        of exciting mood as in the Aliens movie.


-Ed L