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Mr. BIOS 386DX settings

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DamienC

Experienced Member
Joined
Aug 2, 2010
Messages
72
Location
Southern NJ USA
I've got a 386DX-40 on an unknown motherboard with a Mr. BIOS chip. The board also has 128k of cache.

I'm using the default settings in the BIOS for everything. The system seems kind of sluggish for a DX-40. I'm wondering if maybe I need to change some cache or chipset settings in the BIOS. Mr. BIOS seems to have a lot of options for write-back and write-through cache and I'm not really sure what to choose.

I'm not ruling out the possibility that some of the cards I'm using are bottlenecking performance; the system currently has a very old Paradise 256k VGA card as well as an old Seagate ST1144A 120mb hard drive.

Any advice?
 
1: Most improvement for gaming / Windows 3.1(1): upgrade your VGA to S3, ATI Mach64 or ET4000.
2: Some improvement for gaming / Windows 3.1(1): upgrade your HDD to a WD or another more recent IDE HDD.
3: Play around with the BIOS: most aggressive to least aggressive: test it (usually a system crashes / the VGA looks weird). The nice thing is rebooting DOS machines is really fast.
4: Enable SMARTDRV whenever possible. Plug in more RAM if needed to facilitate this.
 
1: Most improvement for gaming / Windows 3.1(1): upgrade your VGA to Diamond Speedstar Pro, S3, ATI Mach64 or ET4000.
2: Some improvement for gaming / Windows 3.1(1): upgrade your HDD to a WD or another more recent IDE HDD.
3: Play around with the BIOS: most aggressive to least aggressive: test it (usually a system crashes / the VGA looks weird). The nice thing is rebooting DOS machines is really fast.
4: Enable SMARTDRV whenever possible. Plug in more RAM if needed to facilitate this.
5: Load UNIVBE before playing games that support the VESA standard.
6: Try this TSR: 386to486.arj: http://www.dcee.net/Files/Utils.
 
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Part of the reason for putting this system together years ago was to experience the system I had growing up, so I'm reluctant to upgrade hardware. But I do have a 1mb STB ISA video card I could always throw in just for testing. I'll fiddle with the BIOS some more when I get home, although doing so the first time didn't really produce any good results. Already got SMARTDRV loaded, and have the Paradise card's VESA driver (although I don't have any VESA games or apps on this thing currently).

As for that TSR, I remember downloading that thing (or something like it) back in the 90s. I always thought it was a hoax/joke program.

EDIT: I'm fairly certain it is a joke and I'm dense. :p
 
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Without upgrades you are probably stuck with BIOS tinkering and a slow(ish) machine. Then again: it is a 386DX40: not a high power 5X86. :D Does your machine have the exact configuration it had back when?
 
It's actually better than original; it's a Zeos 386SX case. I still have the original motherboard, but I broke off a capacitor back in my stupider days.

It doesn't run terribly, but I still expected it to be a bit snappier. I ran Doom on an old 386DX-40 I had years ago and remember it running well with the largest screen size and low detail mode, with this machine I have to shrink the window pretty small for it to run at a playable framerate. I don't really want to play Doom on this machine (I have a POD83 machine for that), I'm just using it as a benchmark.
 
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DamienC said:
It doesn't run terribly, but I still expected it to be a bit snappier. I ran Doom on an old 386DX-40 I had years ago and remember it running well with the largest screen size and low detail mode, with this machine I have to shrink the window pretty small for it to run at a playable framerate. I don't really want to play Doom on this machine (I have a POD83 machine for that), I'm just using it as a benchmark.
Click to expand...

Doom runs well on a 486DX2 or Pentium. Your mind is playing tricks on you :)

Anyway, you really need to get some benchmarks to get some hard facts. Go this this site: http://www.vogons.org/viewtopic.php?f=46&t=37844

It's a VGA benchmark database project. Download the ZIP, it has the benchmarks and a convenient start menu.

And, as mentioned, the VGA card plays an important role in gaming performance:

 
Doom runs well enough on my 486/33 not super well but okay

Keep in mind clock for clock a 386 will be about half the speed of a 486 so about equal to a 486/20!
 
If your 386 BIOS has settings for write-through / write-back cache then you must have one of the very late 386 boards. Things that you might want to look for that will boost the performance are the following:

1. Make sure the board jumpers are set for 40 MHz CPU clock. It sounds silly, but if anyone has ripped some of them off, it might have lost the original configuration and might be running at lower speed. If you have no manual and it does not write the jumper settings on-board, then you can try a CPU benchmark. It will be obvious there.
2. ISA BUS clock (Or whatever the BIOS calls it): If the BIOS has such an option then the values for it must be something like : "7.198MHz, CLK/5, CLK/4, CLK/3, etc". This one controls the ISA BUS clock speed. For 40MHz CPU I would try CLK/4 or CLK/3 (overclocked ISA BUS to 10+ MHz). Believe me, those ISA cards are pretty stable and the video performance gain is measurable with higher ISA BUS clock. If you have stability problems you can try to lower it.
3. Cache and memory timings. The tighter the faster. It is all about how tight you can set without being unsable. Memtest86+ installed in bootable floppy is very good for testing cache+memory stability. I suggest version 4.00, as I've had problems with anything newer than that.
4. Do not load junk in config.sys - autoexec.bat. Things like antivirus-shields or any needless utility are doing nothing other than slow you down and decrease the conventional memory availability. HIMEM.SYS, EMM386, HIGH,UMB settings, FILES=30, maybe CD-ROM driver and then the sound card, mouse driver, the vesa driver (if needed) and optionally smartdrv, all these in "loadhigh" mode (maybe run memmaker to do it byitself)
 
Lots of good replies, thanks all. Mau1werf1977, I'll try running the benchmark later tonight when I'm home. Working some overtime this week, haven't had much time to mess around with the 386.

Board jumpers are OK as far as I can tell. Have looked all over for jumper settings for this board and I can't find anything anywhere, but I'm pretty sure the bus & CPU speed jumpers are clearly labeled and set properly. Can't say for sure because I'm not looking at the board right now. IIRC when I got this board 2 or 3 years ago I messed around with the clock settings and overclocked either the CPU or the bus but it wasn't stable. I'll try again tonight.

Autoexec.bat & config.sys are pretty lean; himem, emm386, smartdrv, Sound Blaster Pro driver, and a mouse driver. Everything loaded high, and I do have DOS=HIGH,UMB and FILES=30.

I do think that maybe the slowness is partially all in my head; after all it's been a while since I had a 386 system up and running. Nothing on the machine really runs that poorly. :p Even the stupid Colorado Jumbo tape drive still works (and it still has backed up data from 2002! :p).
 
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