First post, by Blzut3
On and off I've been poking at an interesting issue with my Biostar M5ALA based K6-III+ build. I've already documented a quirk with Quake and the way the board initializes the CPU. The board also seems incapable of ACPI throttling in its default state. That's not even mentioning that fiddling with some of the memory settings literally bricks the BIOS requiring a reflash. So I'm very much inclined to blame the board here. However, I wanted to post here and see if anyone had any idea on how I might go about narrowing down what exactly is the cause of the freeze while playing Doom. If nothing else the specificity of the freeze is intriguing to me.
In short what happens is that in pure DOS after some time of playing, usually very short, Doom will simply lock up. Most of the time this will be accompanied by what I would call tearing in the picture (1 pixel black bars inserted throughout the image), but can just be a straight freeze.
The interesting thing is that Doom seems to be the exception to the system's stability. I've run through the entirety of Heretic in one sitting with no issue. Hexen is fine. Wolfenstein 3D is fine. Descent seems to be fine. At least one episode of Quake can be completed at 320x200 just fine (may need more testing here). The Need for Speed works fine. Also I can seemingly timedemo Doom all day long without issue.
While I haven't tested it scientifically Doom 2/Final Doom seem to be more stable with runs generally lasting longer but will eventually freeze. This includes running doom.wad with the respective executable. I have confirmed there's no corruption in doom.exe.
My question at this point: is there a good list of games that use Mode Y like Doom so I can check that suspicion? Though I believe that should include Quake no? Also are there any particular games or programs that I should look at as general stability tests?
Things I've tested so far without success:
- Changing RAM module to completely different size/brand.
- Stripping all components from the build besides drives, sound, and video.
- Changing video card to Geforce 2.
- Safe mode boot.
- Disabling motherboard cache
- Disabling L2 cache
- Running at stock clocks and underclocking
- Running with sound disabled
Things that seem to avoid the issue:
- Lowering the FSB from 100MHz (even 95MHz)
- Running under Windows 98SE (which also fixes ACPI throttling)
- Running with EMM386.
- K6-III+ 450 (stable at 600MHz@2.0V in everything besides Doom)
- Biostar M5ALA (BIOS 1105 with 128GB hard drive mod)
- 1 DIMM 256MB Micron PC133 (it's ECC but ECC function of board isn't functional, had to try it though)
- 3dfx Voodoo 3 3000
- Realtek Fast Ethernet
- DC-315U SCSI (no devices attached at the moment)
- VIA based USB 2.0 card
- Aureal Vortex 2
- Sound Blaster 32 (CT3670) with 2MB of RAM
- Corsair TX550M PSU (120W minor rails)
- 10GB hard drive
- 3.5" Floppy
- 5.25" Floppy
- DVD ROM
- Seagate Tape Drive
As an aside the Voodoo 3 seems to show very minor artifacting in Doom/Heretic/Hexen while using write combining. This artifacting goes away when the Geforce 2 is installed, and ultimately I believe it to be harmless since everything otherwise seems to work (including the 3D acceleration).