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Problem running Doom on a ZEOS 486-DX Tower

W

Whoo

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Joined
Dec 26, 2011
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15
I got around to replacing the CD-ROM drive in my ZEOS tower (as the previous one opened and closed on it's own non-stop,) so naturally my first idea was to install Doom on it. It installed fine, but once I started it the problem showed up: I was barely getting 1FPS.

At first I thought it might be the virus scanner that was installed, but after removing it there was no change.

I'm at a loss for what the problem is right now. The only guess I can make is that there's something wrong with the video card or the CPU. I have an old Tandy that's weaker than this machine and it manages 15-20FPS average. Here are the specifications of the ZEOS tower:

CPU: Intel 486-DX @ 50MHz
RAM: 16MB SIMMs
GPU: Diamond Computer Systems SpeedStar 24
OS: MS-DOS 5.0 and MS Windows 3.1

And here are the contents of AUTOEXEC.BAT and CONFIG.SYS:

AUTOEXEC.BAT
CONFIG.SYS

Any ideas?
 
First thing I see - in your Config.sys, why are you loading 2 CD device drivers? Your MSCDEX.EXE in autoexec only calls sscd000; you can safely delete the sbcd.sys line in your config.sys, as it's doing nothing for you but eating precious memory.

DEVICE=C:\SB16\DRV\SBCD.SYS /D:MSCD001 /P:220
DEVICEHIGH=C:\SAMSUNG_\SSCDROM.SYS /D:SSCD000 /V
Click to expand...

If deleting the above didn't help, then you might want to disable all audio and music in the game, see if that has an effect on your fps.

Might also be worth doing a completely clean boot - no sound drivers, ems, etc - nothing but pure DOS (just rename config.sys and autoexec.bat to *.old). Then start up Doom again and see how it goes.
 
You may also want to turn EMS off - use the NOEMS version on your emm386 line... Doom is a protected mode game and doesn't use or need EMS.

The clean boot suggestion is probably the best though. If that doesn't make a difference then there's a hardware or BIOS setting problem - Doom should fly on a DX-50
 
btw, you can add REM to the beginning of the lines vs deleting it. Alternatively you could make a dos boot disk and boot off that to test different memory uses. Could also (can't remember if dos 5 had it or dos 6) run memmaker which will analyze your config.sys and autoexec and look for placing things elsewhere but that was generally to free up conventional memory, wasn't a factor with programs that used dos4gw. Have you tried any other math intensive games?
 
Maverick1978 said:
First thing I see - in your Config.sys, why are you loading 2 CD device drivers? Your MSCDEX.EXE in autoexec only calls sscd000; you can safely delete the sbcd.sys line in your config.sys, as it's doing nothing for you but eating precious memory.



If deleting the above didn't help, then you might want to disable all audio and music in the game, see if that has an effect on your fps.

Might also be worth doing a completely clean boot - no sound drivers, ems, etc - nothing but pure DOS (just rename config.sys and autoexec.bat to *.old). Then start up Doom again and see how it goes.
Click to expand...

Yeah I forgot to get rid of the SB CD-ROM driver. I deleted it from CONFIG.SYS shortly after posting this.

Anyway I disabled all audio and music with no avail. I did a clean-boot and got the same problem.


barythrin said:
Have you tried any other math intensive games?
Click to expand...

I tried Heretic (which uses the same engine,) and it also was barely getting 1FPS.
 
UPDATE:

Been getting some help from some people on another forum, and they suggested me to use Snooper to see if the CPU was running at 50MHz. Turns out it was not; it was running at 13.7MHz.

The board has no visible jumpers to control the clocks of the ISA buses or CPU speeds, and the CMOS Setup has something called a "Timing Set," which is able to modify the speeds of the CPU. It has speeds of 20MHz, 25MHz, 33MHz, and 50MHz, but I haven't been able to get it to go over 22MHz.

I was also advised to get a heat-sink (as there currently isn't one) if I go over 25MHz, as the 486 would cook the system.
 
Check the turbo switch, that could slow it to a crawl.
 
Actually it turned out the motherboard the CPU's plugged into only supports default speeds of 20, 25, and 33MHz. How and why a 50MHz 486DX was chosen to be installed I'll never know.

After making a really cheap heatsink mount, I started up Doom with the Turbo button pressed in, which I have set to run the CPU at 50MHz. Framerate is much better now, with only large open areas getting bogged down.
 
dx-4 80? o_O

Not to be a chip nazi, but sure you dont mean dx4-75, dx4-100 or dx4-133? I dont recall there being a dx4-80. I do know you can oc an 486-dx2 66 to dx2-80. Also the P83 overdrive... :confused:

As for Doom running slow , if your system passes all ram tests, and the cpu is working correctly, next I test if that cpu cache is working. Without it that system will be SLOOOOWWWWWW. Considering you have a ET4000 video card, doubt its the video card unless your system has issues with FAST writes on.
 
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WOW! Never knew dx2-80s existed! :O

I must obtain one for my collection now. And I thought I already had every speed 25-100. :eek:

Sx 25/33/40 , Sx2 50/66, Dx 25,33,40,50, Dx2-50/66, dx4 75,100 , and SLC 40,50, plus 5x86 100 and 133 are what I have.

Now I realize im missing a couple! the Dx2-80 and Dx4-120. Arg where am I going to find those, the sx2's were hard enough to find! ... *bangs head on keyboard
 
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Just hit me, what version of that speedstar 24 do you have?

They came in 2 flavors, the original which is a et4000ax or w/32 forget which, and the 24x which is a western digital chipset. If its the ladder, I recall there being a VESA TSR that speeds up VGA performance.

Little searching provided me with the package >.>

http://support.gateway.com/support/...lities and driver, version 2.02&uid=338469269

Dos utilities and driver for your card ^
 
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Well it's atleast 1 i didn't expect to see in one of my old pc's, don't know how unusual it is tho and i've yet to get any cyrix/via cpu's either in pc's or alone, man i'm angry i junked pc's i could have ripped the cpu's out of like P90's and P75's :/ but i did take out a lot of spare parts from them heh.
 
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