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Some questions about 2 386DX-40 mobos

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First post, by keropi

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Hiya!

I recently got gifted these two mobos, they work fine and I've replaced their batteries with coin ones successfully. I have some questions about them because quite frankly back on the 386 era I did not bother much with upgrades etc...

34oo4zk.jpg

The left one has the cpu soldered in an adaptor with pins. Can you fit anything else other than a 386 there? (ie can you upgrade it to a 486?)
Also do BIOS updates exist for such mobos? Both have the same AMI bios with the puke color scheme 🤣 , should I bother searching for updates? Obviously I don't really know their maker/models yet since I have left them at my office and the pics I took do not help 🤐

Regarding HDDs, am I locked in those pre-defined types and have to use overlay software for bigger ones? Can anyone recommend a nice I/O card with some buffered hdd access? I have some generic 16bit ISA ones but they are nothing special IMHO (or I should not pay attention to that since the system will be a 386 after all?)

I am excited to build a working system (thinking to use the left mobo with the soldered 386DX) since I never had the joy of using custom made 386/486 (I went from IBM 386 to Zenith 486 that also had most devices onboard). I also think I'll add a Cirus vga with a 8bit SB (or sbrpo) and maybe my GameBlaster , no point having it stored 😁

Thanks for any info/comments/ideas 😊

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Reply 1 of 69, by iulianv

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Nope, 386 only. Well, also Cyrix / Texas Instruments 486DLC (386 pin-out with some 486 instructions and 1KB of internal cache), but I doubt there's an option in your BIOS to enable that cache (a software utility to enable it does exist, but I couldn't get it to work - I didn't bother too much either, there are many success stories out there 😀).

BIOS images for such old boards (I'm thinking 286 and 386) do exist too - you'll probably have to identify your board as accurately as possible, figure out if the available BIOS is newer than yours and find a way to erase/program EPROMs 😀. I found these two sites interesting:

http://sannata.ru/bios/
http://chukaev.ru54.com/bios.htm

All of my 386 boards (five at the moment) require overlay software (or the XTIDE "universal BIOS", but I haven't tried it so far) to be able to "see" more than ~500MB in DOS. I'd love to get my hands on a "BIOSed" ISA IDE controller (like Tekram or BusLogic), but I'm not expecting that kind of luck anytime soon...

Reply 2 of 69, by keropi

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I see... thanks for the info iulianv , it does clear up some stuff
on the cyrix matter, I do have a clip-on 486slc2 in my IBM386sx machine, you have to run a program in autoexec to enable the 1kb cache that DOES make a huge difference! maybe the utility you tried was not the correct for your upgrade?

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Reply 3 of 69, by iulianv

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I used the tools in an archive named "cyrix100.zip", which I tested on an ASUS ISA-386C board with both Cyrix and Texas Instruments types of 486DLC-40 - that experience is summarized somewhere on the second page of this thread:

Texas Instruments 486SXL2-50 or TX486DLC/E-40GA

The board on the left looks a lot like one of these (PCChips, judging by model number and soldered cache? 😀):

http://stason.org/TULARC/pc/motherboards/U/UN … 0386-80486.html
http://stason.org/TULARC/pc/motherboards/U/UN … -326-VER-2.html
http://stason.org/TULARC/pc/motherboards/U/UN … -486-M-326.html

Reply 4 of 69, by Markk

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I think that it's not worth trying to upgrade the BIOS on a 386. Things are much simpler on such a board compared to the 486/pentium stuff, and even if an update is found, I doubt if it's going to make much difference.

The AMI 386 BIOS setup screen color scheme usually is able to change(F2/F3 keys I think).

And I remember that almost every 386 board using AMI BIOS I've seen, has an option to enable CPU Internal Cache memory (Even if the board has a soldered PQFP CPU which obviously can't upgrade to a 486DLC).

Reply 5 of 69, by elianda

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Well, nice that you consider building a 386 system.

First a note about the AMI BIOS. The startup colors are for monochrome monitors and just look strangly colorful on a color screen. I recommend pressing F3 as soon as you enter the BIOS because the next profile is ok on a color screen. The second thing is that there are indeed different AMI BIOS versions. The difference is usually not too obvious, but f.e. the later BIOSses feature already HDD detection and there might even be options for enabling Cyrix Caches.

As FPU I recommend ULSI or Cyrix FasMath.

As for the HDD problem, I would like to remind you that at that time HDDs had a size of about 100 MB and noone bothered with the 540 MB limit. Anyway, try to grab an Adaptec 1542x SCSI controller (best with Floppy support). Those controller support 1 GB size. Disadvantage is that they are located at 0x330h and you loose some kB UMBs.
Also consider if you really need more than 540 MB on a 386. This is quite a lot for DOS.

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Reply 6 of 69, by keropi

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Thanks everyone for all the info, more things make sense now to a spoiled IBM/Zenith old user 🤣

I couldn't resist and went to the office to tinker more seriously with the mobo I want to use.... 😁
First 2 pics of the 2nd mobo, it's a M326 like iulianv pointed, a v5.2 too... Pic1 pic2

and here are some pics of the mobo I plan to build a system with:

deuuc9.jpg

vhcf1c.jpg

and here is the coin-battery "hack" , I had to relocate the holder on top of the BIOS chip because there was no room for it in the original position 🙁

2iu6ayp.jpg

it appears the mobo is a MB-1333/40UCQ-A v1.1 one, I think it's this mobo HERE and IIRC the BIOTEC chipset is a rebranded one? UMC?
I found 8 matching Samsung 1MB simms, so now I have 8MB installed 😁 which is more than enough IMHO 😀 And I also found a GoldStar I/O card and a CL-5424 1MB vga. I think the build is coming along nicely 😀 , still haven't decided on the sound part and I don't really have a suitable AT case for it 😖
More as I slowly progress with it 😁

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Reply 7 of 69, by CapnCrunch53

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Nice, I like the coin-battery job you did, very clean looking. I need to do that on my 386 sooner rather than later. Mine has the external header though so I'll just mod a pc-speaker wire.

PCs, Macs, old and new... too much stuff.

Reply 8 of 69, by keropi

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thanks CapnCrunch53 😀
personally I don't really like it 🤣 but it will do... I should have soldered a different and smaller wire but got bored and just went with it...
the mobo did have an external battery header but I prefer to have it onboard as the modification is a simple one, a diode and a coin cell holder (in this case a small length of wire needed too 🤣)
I wish I could find an AT case as easily as the US though....

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Reply 9 of 69, by feipoa

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Shown below are 386 CPUs from my collection which are probably the best 386 upgrade options available (aside from the odd-ball IBM DLC3 piece at 75 (3x25) or 100 (3x33) MHz).

The first one is a TI/Cyrix 386 upgrade CPU (SXL2-50) that runs at twice the bus frequency, so 25x2 = 50 MHz. You will need to use software to enable the 2x multiplier. This CPU also has 8 KB of L1 cache, as opposed to only 1 KB with the Cx486DLC. You can also run this CPU with a 1x multiplier and a 40 MHz bus.

Next down the line is an SXL-40. It also has 8 KB of L1 cache, but does not have the 2x multiplier option. As with the SXL2-50, the SXL-40 needs software to enable the L1 cache if your motherboard's BIOS does not support enabling of L1 cache. In cases where enabling the L1 cache in software fails, I beleive Cyrix made an interposer board which empowered motherboards without native L1 cache support to still use the L1 cache. Cyrix had a special name for it, but I have forgot it now.

The SXL CPUs were not very common and I think were mainly available outside of N. America and in OEM-only applications. I do not believe they were licenced for single CPU upgrades. According to vogons member Anonymous Coward, Texas Instruments decided to add more cache to Cyrix's 486DLC design without approval; this angered Cyrix and eventually led to a falling out between the two companies. Cyrix then went to IBM for use of their fab.

The next two CPUs down the line are the more common Cyrix/TI 486DLC's which ran at 40 MHz and have 1 KB of L1 cache (as opposed to the Intel and AMD units with no L1 cache). Again, software is needed to enable the L1 cache if not supposed natively in the BIOS. I have not had any problem enabling the cache on these CPUs with a simple program called from within the autoexec.bat file on start-up. It gave quite a speed boost.

I hope this information helps.

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Reply 10 of 69, by keropi

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thanks feipoa for the detailed info 😀
looks like I will need to solder a cpu-socket if I decide to use any of these upgrades 🤣
for now I'm gonna keep it a 386DX I think...

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Reply 12 of 69, by Seaside

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Nice mobos you got there. I have exactly the same mobo (BIOTEQ - uses UMC Chipset). Mine has socket for the CPU and FPU.

I got it with a ti486DLC and with FPU. The speed difference between 386 and this one wasn't so big as expected but there is a difference. I think mine has HDD auto detection feauture. The 386 board i have is very new (1993) and has AWARD 4.50 bios with HDD auto detection.

My 386DX40 mobo shows 6.39 in Speedsys (with fpu onboard) and this BIOTEQ board i have with the DLC40 CPU shows 8.99 in Speedsys and 21.5 in 3Dbench with Ati Mach 32 or S3 805 ISA card.

I didn't run any SVGA games yet as i don't have time this period. But i will try for sure Trasnport Tycoon and Doom/Doom II to see how they run with the DLC.

Also check this page

http://ps-2.kev009.com/sandy55/Interposer/386 … Make%20it%20486

@feipoa

I didn't know that a program is needed to make these DLC's run faster.

Can you lead me please to find it and test it ?

Thanks.

Reply 13 of 69, by feipoa

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Did you try these? I think some are for the DLC, SXL, SXL-2, and DRx2.

http://homepage3.nifty.com/sandy55/Program/MAKE486.EXE
http://ibmmuseum.com/ohlandl/8570_Tim_OConnor/Cx486DRx2.EXE
http://www.mediafire.com/?hb4ci9bq59jgxqi

Luckily, the program I use for the Cyrix/TI 486DLC has a GNU General Public License and I have attached it here. I have a few others, which may be the ones above (or not?), but I couldn't find a license.

The Speedsys for my TI486DLC is attached. Speedsys doesn't seem to show the 1 KB of cache, but the benchmarks did show an improvement when the software enabled the cache.

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Reply 14 of 69, by Seaside

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feipoa wrote:
Did you try these? I think some are for the DLC, SXL, SXL-2, and DRx2. […]
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Did you try these? I think some are for the DLC, SXL, SXL-2, and DRx2.

http://homepage3.nifty.com/sandy55/Program/MAKE486.EXE
http://ibmmuseum.com/ohlandl/8570_Tim_OConnor/Cx486DRx2.EXE
http://www.mediafire.com/?hb4ci9bq59jgxqi

Luckily, the program I use for the Cyrix/TI 486DLC has a GNU General Public License and I have attached it here. I have a few others, which may be the ones above (or not?), but I couldn't find a license.

The Speedsys for my TI486DLC is attached. Speedsys doesn't seem to show the 1 KB of cache, but the benchmarks did show an improvement when the software enabled the cache.

Thank you very much. Lots of goodies here.

Now which one i should use ? according to your experience ?

Do i need to syntax something or i'm just running the exe/com files ?

The ti486 dlc's i have are showing 14 MHz in speedsys and much lower memory bandwidth. I test them with 4,8,14,16,24,32MB but my numbers seem pretty low compared to your system.

Reply 15 of 69, by feipoa

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If you are only testing a Cyrix 486DLC, use the program I have uploaded. There is a readme file that explains which commands to use.

Speedsys showing 14 MHz is fine. I sometimes get a 14 MHz reading on a 486DLC. Speedsys shows 50 MHz for my DLC, but it is being run at 40 MHz.

The Speedsys memory bandwidth may not be accurate. Please post your Speedsys screenshot so we can see the cache and memory speed on the chart.

Plan your life wisely, you'll be dead before you know it.

Reply 16 of 69, by keropi

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so the 486DLC gets a 10.15? doesn't seem much of an improvement over the 9.31 I get with a 386DX/40 (both mobos get the same cpu score btw) or is this shot taken without the L1 cache enabled?

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Reply 17 of 69, by feipoa

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@Keropi
I don't recall if I took that with cache enabled or disabled, but I'd assume enabled. I'll have to check this again. More important than the final Speedsys score is the change in score from cache disabled to cache enabled. Each motherboard/chipset performs differantly and ideally you want the fastest chipsetted motherboard and cache enabled. Speedsys may also not correctly score a system with 386 cache enabled because it isn't expecting L1 cache on a 386. It is better to get a broad range of benchmark scores.

Refer to this thread,
Texas Instruments 486SXL2-50 or TX486DLC/E-40GA

On page 3, I showed a comparison with the Landmark benchmark program, having L1 enabled and disabled, whereby with L1 enabled, it indicated a 50% performance boost. Vogons member Anonymous Coward has a 386 motherboard who's BIOS natively supports the L1 cache. I remember his 386 score with a 486SXL being significantly higher than a 486DLC.

According to some TI or Cyrix upgrade software I tested, apparently my 386 board doesn't support software-enabled L1 cache and needs some specific interposer from Cyrix. This may explain also why Speedsys doesn't show a higher score, however Landmark picked up on the L1 cache anyway.

I got 10.15 with 256 KB of L2 cache and 10.53 with 128 KB of L2 cache.

I would encourage more people with 386 motherboards to experiment with Speedsys and the 486DLC. My 386 board has a CHIPS chipset (no, not PC CHIPS) and is particularly fast with its L2 cache and RAM.

Plan your life wisely, you'll be dead before you know it.

Reply 18 of 69, by keropi

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Well both the mobos pictured here have the option in BIOS to enable L1 cache (ofcourse it only makes sense on the one with the cpu socket) but I have no 486 upgrade chip to test.
What I have is a 486slc2 installed in my PS1/pro , without the cache I get similar speed as the onboard 386sx/20 , but when you enable the 1kb cache with Cyrix's program then it becomes almost double as fast... if it is of any interest I can make some tests that you will tell me feipoa

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