Glad you liked my gibberish.

4x1Mb Samsung 60ns parity FPM 30 pin SIMMs

Had to pick and choose from a bunch to find the right ones. As far as i remember 2 more memory sticks with LG chips on them worked fine too, but used the 4 Samsung ones for uniformity.

The BIOS does not offer option to toggle parity checking, but these memory sticks have been battle tested on multiple motherboards for all sort of things - they are solid.

EDIT:
Just remembered something - there is a similarly looking type of SIMMs with KM41C1000CJ-6 labeled Samsung chips on them, they gave me quite a bit of trouble. They are a bit taller and have wider resistors. There is a "SAMSUNG Korea" label in the upper left corner.
But maybe it is just a coincidence that mine are not great and i am only spreading rumors here.
So i leave it to you to decide what is what. 😀

nice 😀
i didn't know that samsung is good too 😀

if I'm not mistaken, then "Parity error check" is it J18, you need to install a jumper 1-2.
2-3 - OFF parity error check.

I see chips "Parity Error Check" are also high speed 60ns 😀

I tried that and got an error message.
Plus the system hangs in a weird way.

Tried the same memory sticks in two other motherboards - 286 and 386 - parity check went just fine.
Given the fact that the VLSI system is very stable, i am wondering if its parity checking is just being funky ?

Btw, do you have the datasheet of the motherboard ?
There are couple of other jumpers that seemingly do nothing.

you can check by turning turbo is OFF. Will it pass the test?

Datasheet/document I have no.

With Turbo turned-off the parity check function works, otherwise it fails.

Didn't see the 3dfx voodoo get used in benches on the DX5. 🙁 Awesome collection though. Nice job.

Thanks for the kind words.
It is a nice hobby to spend an hour or few with, when possible.

You are right - i didn't provide any numbers for the voodoo. Let me know if there is a specific benchmark, or a game, that you think will be a good fit and i can give it a try.

===========================

I want to righten something that was wrong, or better - something that was unjust.
Couple of posts above i labeled the Unichip 367C motherboard an underperformer.
The motherboard shown all symptoms of turbo turned-off - no L2 cache, very low performance, etc.
I was unable to wake it up, so i assumed that it is just a badly desgned piece of hardware.
Until yesterday.

Check this out:
- I noticed that one of the turbo-switch pins was little shorter. Upon close inspection i realized that it actually was broken and does not make contact with the corresponding line. Fixed it. Shortened the pins (turbo-on). Back in business ! Until ...
- Now there is an error message about bad cache.
- I know that the cache chips are good. They work fine in other motherboards. Whatever. Changed couple of sets, until 4xEtronTech 20ns ones did it. Weird. Finally ! Well, until i ...
- Turned-off auto-config and optimized timings = black screen.
- I was using CL-GD5426 and CL-GD5428 ISA video cards. Had to bring my preferred weapon of choice - ET4000AX (1998) when something is funky on that side.
- Back online. No, not yet ...
- The system is now very unstable. I know that the installed memory may not be the best out there. Swapped them with trusted ones. And finally that did it !
Quite a tall stack of problems that i think gives me a good excuse for my initial opinion about this motherboard.
Once that was cleared up, the motherboard turned out pretty nice.

Updated stats:

Performance comparison with M321 for reference:

Back in the day there were plenty of S3 Virge based video cards.
Spent a moment today to check the unaccelerated DOS and accelerated Windows GUI performance of 3 Virge generations (capped at 1996).
Added an S3 Trio for reference.
Used the ASUS PVI-486SP3 motherboard.
System's performance will be hard CPU limited, but still, let's see what comes out of it.

S3 Virge/GX 2Mb (Compaq)

S3 Virge/DX 4Mb (forgot to put the second 2Mb of memory for the photo session)

S3 Virge/VX 8Mb (STB Velocity 3D)

S3 Trio64V2/DX 2Mb

As expected, DOS results are even, a bit of a difference in Windows GUI. Same old, same old.
Will try to run some accelerated 3D tests tomorrow to see if there is anything different on that side.
If i can trust my distant memories - the results will be close, but also dismal. 😀

Ran a quick test with latest version of glQuake1 against the 3 Virge cards using the GL library provided by S3.
Used Voodoo 1 as a reference, but had to set "cache burrst write" to 3 cycles (lowest possible is 2), otherwise Voodoo and glQuake don't cooperate. This was not necessary for the Virges.
I expected VX to be the slowest, but surprisingly it does better than the rest. Still the Virge line is clearly a 3D decelerator type of hardware.
On top of that, picture was dithered and the GX card produced additional texture stretching artefacts.

In continuation to my post on Page 2 about 486 motherboards from the time period 1995-1996, i am adding one more to the list - Biostar MB-8433UUD-A

Revision 2

Revision 3.1

The motherboard came with the usual dead Dallas battery, which required unsoldering and socketing.
The cache chips were faulty, so fresh high-quality ones had to take their place.
Memory was problematic too, so high-quality modules had to replace them as well.
Adjusted BIOS timings to the lowest possible wait states for best performance.
Significant amount of time was spent on finding the right SRAM chips. Board is extremely picky.
Used Feipoa's tweaked BIOS.

Biostar MB-8433UUD-A

benchmark results

Once the SRAM hurdles get resolved the Biostar MB-8433UUD turns into a really great motherboard.
Stable, fast and flexible. Its on-board controller can be better, but there are plenty of cheap third party options that can be used instead.

---

1024Kb L2 cache mod and improved performance at 160Mhz without compromised stability - here

The story continues with stable overclock to 180MHz (3x60) explained here.

A special guest on this weekend's matinee was Microstar MS-4144.

I happen to have a ver:1.0 of the same motherboard. There are also versions 1.4 and 2.1 out there.
There are some differences between them.
Most notably later versions have many components omitted compared to version 1.
Not sure what to make out of it. The two motherboards here have exactly the same behavior and characteristics.

Jumpers are a bit all over the place. Took a moment to figure them out.

Components used for testing:
VGA: Matrox Millennium PCI 4Mb
RAM: single stick 32Mb 60ns FPM
L2 CACHE: 1Mb for 160Mhz, 256Kb for 180MHz. WB mode.
LOCAL STORAGE: CF card with adapter plugged into the on-board IDE controller

Experimented with 3 BIOS versions, where: default AMI < latest AMI < latest AWARD.
The AMI microcodes have issues:
- System is slower than with latest AWARD.
- IDE performance is in the range of 2.5Mb/s compared to over 7Mb/s with AWARD.
- IDE write issues with CF cards. Attempt to write can easily result in corrupted file system.

--- AMD Am5x86 at 160MHz (4x40)

Without further ado - i expected a lot from this motherboard based on its impressive specs (256Mb RAM, 1024Kb SRAM), but got disappointed. The system is unstable when timings are too tight. Increasing them to keep things stable leads to worsened performance. Tried different sets of RAM and SRAM chips to eliminate the chance of incompatibility, but the problem seems to be the mobo itself. It is kind of strange, because the same SIS chipset works much better in other boards. Used the same Matrox Millennium PCI video card for the tests below.

My initial tests were incorrect. The 1024Kb L2 cache was not actually working, so i drew the wrong conclusions from there. Also, i was using the default AMI BIOS which turned-out to have significant performance issues.
With these issues correct i ended up with working 1024Kb L2 cache, all BIOS settings on max, except DRAM RAS TO CAS DELAY = 3 (best is 2).
Motherboard is fast and stable.
Not picky about L2 cache chips which is rare.
Things just work.

The last tests were done with version 1.0 PCB, where the L1 cache is automatically put in WT mode. The SpeedSys screenshot from it.

benchmark results

--- AMD Am5x86 at 180MHz (3x60)

Applied the simple mod described here to enable 60/66/80MHz FSB.

Tried hard to get 1Mb level 2 cache working but without success - POST never completes no matter what.
Same applies to 512Kb configurations.
I have several trusted sets of chips that handle 180/200MHz configurations in other boards just fine, but not in this case.
The problem is clearly on the motherboard side.
Things got under control with 256Kb only and the slowest BIOS timings.

Level 1 cache in WT mode.

The system feels quite stable, but the Quake 1 test is consistently failing, which is not great.
Performance is below average compared to what other motherboards show in this category.

benchmark results

--- AMD Am5x86 at 200MHz (3x66)

This configuration is possible but was not able to achieve stable system. Moved on.

--- AMD Am5x86 at 200MHz (4x50)

Chadti99 examined the board at 200MHz (4x50) here.

benchmark results

--- Intel P24T (POD100, 2.5x40)

The two motherboards were unstable with POD100 CPU (modded P24T for stable 2.5x40MHz). Tried hard, but not luck.
The do work however with POD83, but that is of little interest to me and didnt waste time to capture perf numbers.

As a brief conclusion - a nice piece of hardware, extra RAM is a plus. Performance is not the best, but in the ballpark. There are better boards out there.
One of the best late 486 motherboards out there - fast, stable, just works.

Another weekend - another motherboard examined - Elitegroup US 3486, although FX-3000 rev 1.0 is printed on the PCB.
Actually the examination happened a while ago, only sharing the findings today.

Motherboard is fully stable at 45MHz with all system timings at their lowest (fastest) available values. Also, fully maxed out system - 32Mb RAM, 256Mb SRAM, etc.
The mobo is fully stable at 50MHz with lowest timings, but without FPU. If FPU is present (a 40MHz rated FasMath, for example) some compromises need to be made for things to stay stable - relaxing some timings and enable caching for the first 16Mb RAM only. Obviously this is a no-go for me, so i don't consider it as an option.
The board works at 55Mhz as well, but timings have to be relaxed which leads to lower performance than 50MHz and even 45MHz.

Surprisingly at 50MHz the Adaptec AHA-1542CF SCSI controller can operate at 10Mb/s which is a real boost for the disk performance. You really feel the 5Mb/s read speed ...
At 45MHz i can get it to work at 6.7Mb/s max.

FX-3000 didn't like 12ns ISSI SRAM chips. Not sure why, because they work just fine in other systems, so i went with 15ns UMC ones, which nicely match the chipset brand of the board.

All tests were performed with the same Genoa CirrusLogic GD-5426 video card with latest (for 1993) Diamond BIOS (great performance), that i use in my main 386 build.

AMD 386DX at 45MHz

AMD 386DX at 50MHz

benchmark results

Not the fastest clock-to-clock chipset and assembly, but very steady beyond the standard 40MHz.
For stable 50MHz ULSI or black-top FasMath FPUs are required.

Finally got some time to get back to the retro hobby.

Played a bit with this Magitronics QD-U386DX ver.1 motherboard based on UM82C482AF/UM82C481BF chipset.

https://www.petershipkov.com/temp/retro_pc_im … motherboard.jpg

The mobo looked very promising at first with its clean and well organized layout, but then came the disappointments.

It was very picky about the SRAM chips. Took me a while to get it to 256Kb.
Very slow local storage I/O and below average VGA performance.
The board does not overclock at all.

Here is what SpeedSys says for 40MHz:

Without FPU 45MHz is possible.
Unstable in Windows 3.11. Couldn't complete the WinTune2 tests.
Numbers are actually pretty ok for what they are, but still one of the slowest 386 motherboards around.

benchmark results

Octek Jaguar V rev.1.3 based on Macronix MX83C305FC, MX83C306FC chipset.
An interesting 386 motherboard with potential, hampered by wacky Mr.Bios.

An interesting board.
On par (clock-to-clock) with some of the best performers out there.
There is only 8Kb cache installed with no options for upgrade. This hurts memory intensive tasks.
Very stable, takes 100MHz crystal oscillator with ease.
The hardware feels capable but the installed Mr.BIOS lacks sophistication - very few wait-state parameters exposed.
There is a later revision 2.0 of the motherboard with higher level of integration, but it replaces the crystal oscillator with clock generator which limits base frequency to 40MHz. Not good. 1.x is the better place.

For 50MHz FSB had to lower "system wait state" which affected IDE performance negatively compared to 40MHz system.
Used ET4000AX video card for DOS interactive graphics and Cirrus Logic GD-5434 card for Windows accelerated GUI tests.
Didn't bother with SCSI controllers. They get unstable at high ISA bus frequencies.

benchmark results

Performance is above average at best.
System is very stable. Just works.
Mr.BIOS is snappy between restarts as usual. Gets to DOS prompt in about a second.
The whole package works really well.

I have been searching for the right 386 motherboard for quite some time.
Went through a lot of them (partially documented in this thread), but never found one that fully satisfies my requirements for speed and stability.
Well, until now.

DTK PEM-4036Y based on Symphony 'Haydn II' SL82C465, SL82C461, SL82C362
256Kb cache, 12ns
32Mb RAM, 60ns, Micron

This motherboard is a real beast.

EDIT (few years later):
Well, all good things eventually come to an end.
Turns-out that MSI MS-3124 version 2.1 is even faster - stable overclock with IBM BL3 processor running at 110MHz (2x55) and ISA bus at 27.5MHz.
But that does not diminish the qualities of the DTK assembly at all. It is still impressive.

1. The fastest (clock-to-clock) 386 hardware i have seen so far.
2. Overclocks to 55MHz without FPU and more importantly - overclocks to 50MHz with FPU with the tightest BIOS timings (* small exception for 3D rendering - noted below).
- A 40MHz FasMath FPU core and 12ns SRAM are needed to operate at this frequency.
- The slightly faster (clock-to-clock) 33MHz marked FastMath FPU core hangs the system.
3. Impressive IDE performance (3.5Mb/s) and even more impressive SCSI performance in 10Mb/s DMA speed mode (5.2Mb/s read and 3.2Mb/s write).
4. Fully maxed-out system (ram, cache, fpu, scsi, sound, lan, etc.).
5. Very stable !

And the best part yet:
Usually getting 386 hardware to perform at 45Mhz or higher involves significant effort.
Not this time - the thing just works.

In addition to that:
Clean and easy to work with layout.
Not a fan of the RTC Dallas modules, but once socketed they are ok.
There is something to be said about the SIMM RAM sockets - the metal clips are so convenient and with just the right grip, so i caught myself messing around with them more than i should, it's kind of addictive in a retro-nerdy-way. Whoever built that board really put the extra effort back then.

As a side note:
I happen to have another version of this motherboard: DTK-PEM-4036YB (notice the B at the end).
In pristine condition with warranty labels all over the place.
Removed the RAM and CPU it came with for the photo (imagine more warranty labels).


In its original plastic wrap (yellowed from the years) with written on it Toshiba Corporation (in Mandarin).

This leads me to think that at least the YB version of the motherboard was produced for some industrial purpose.
Perhaps both versions were for industrial needs since these items are very rare now-a-days.
In fact i had 2 of them, but sold one years ago.
It has proprietary and unusual DTK BIOS.
Does not overclock well.
The board layout and chip types suggest later version, but the keyboard controller is older than in PEM-4036Y.
The serial numbers of the Symphony chips are different between the two mobos.
The SIMM slots are entirely plastic, including the clips, which makes it hard to insert or remove memory modules (this actually prompted me to notice how nice the memory slots on the other board are).
Anyway.

Few comments about the stats and tests:
Until now i relied on CL-5426 based Genoa video card with Diamond BIOS for my 386 activities, but it refused to operate reliably at 50MHz FSB. So i switched to ET4000/W32i for good. It is on par with CL-5426 and ET4000AX in DOS, but does so much better in Windows. At 24bit color it approaches the performance of Artist Graphics's WinSprint accelerator, which operates at 8bit colors only (limited by it's Win3.1 driver - i am playing period correct at all times, so everything has to be that way - for 386 - year 1993 is the upper limit for hardware and software).
While 3D Studio works fine with the tightest timings, for LightWave3D the DRAM wait state has to be increased to 2.
Still, for those who are not into retro 3D rendering (who really is ?), the motherboard will operate completely stable at 50MHz with the tightest BIOS timings at all times.

The "DOOM" 386 build (running at 55MHz with no FPU) showcased in this thread (DooM) achieves 39.5fps and 9.7fps in the Doom test. This mobo outdoes it at 50MHz (25MHz ISA bus). Will try to post results for 55MHz and no FPU at some point later.
benchmark results

As a side note:
I happen to have another version of this motherboard: DTK-PEM-4036YB (notice the B at the end).
It has proprietary and unusual DTK BIOS.
Does not overclock well.
The board layout and chip types suggest a later version, but the keyboard controller is older than the PEM-4036Y.
The serial numbers of the Symphony chips are different between the two mobos.
The SIMM slots are entirely plastic, including the clips, which makes it hard to insert or remove memory modules (this actually prompted me to notice how nice the memory slots on the other board are).
Anyway.

Conclusion:
2 years ago i wanted to build clean 286, 386 and 486 class computers that i am fully satisfied with (as mentioned in the first post of this thread).
The 286 and 486 ones got there relatively quickly with the VLSI and ASUS PVI motherboards.
My 386 effort started with PC-Chips M321 which is impressive board by itself, but didn't overclock well.
Several boards later i was still searching for the right one until stumbled upon this Symphony Haydn guy.
The 386 rig is shiny and sparkly now ... and my 386 journey seems to be finally coming to an end.
😀

---------------------------------------------------------------------------------------
EDIT
(several months later)

Some conversations with Feipoa and Anonymous Coward prompted me to test Texas Instruments 486 SXL2-50 CPU on this motherboard.

All BIOS settings are set to their optimal values for best performance, except DRAM WAIT STATE.
It has to be set to 2 for complete stability in the very sensitive Lightwave3D rendering test.
For everything else it can be set to 1.
This is how i use the PC at the moment.
The below metrics reflect that.
For reference: when using standard 386 processor, if the frequency is below 40MHz - wait state can be set to 0, if 40MHz or higher - wait state has to be 1.

After short experimentation with different configurations, such as clock doubling, register values, etc., best performance was achieved by running the CPU natively (meaning - no clock-doubling) at 50MHz and 25MHz for the ISA bus.
It can operate (natively) at 55MHz as well, but without FPU and not fully stable.
The black top Cyrix 40MHz rated FPU caused stability issues from time to time and after testing several different FPUs the stable configuration was achieved with 40MHz rated ULSI. It is a tiny bit slower than the Cyrix, but stable, which is what matters here.
One big minus is the fact that with SXL2 in the CPU socket CF cards are no go with SCSI controllers, so switched to IDE adapter instead.
IDE+CF >> SCSI+HDD.

Video recording from one of the initial test runs
Few notes:
Video got too long, so cut it here and there.
Phone camera blows-up monitor picture, otherwise the ET4000/W32i produces really nice balanced colors.
Typing with one hand. Made a mistake in the Doom low-res FPS calculation. The result is 59.13, but not 59.35.
After i took the video, i made few more tweaks which resulted in even higher score, as reflected in the chart below.

As you can see - performance is pretty good for a 386 system.
Best results were achieved using: cyrix.exe -e -r -i1 -i2.
benchmark results

Still "debating" if i should replace the standard 386 CPU in use with this SXL2 one.
These CPU upgrades feel too much like cheating, but the extra performance is great.

---

EDIT (few months later):
The next chapter - IBM Blue Lighting 3 processor upgrade.

---

Attached is the latest BIOS.

Amptron 286 VLSI Turbo based on VLSI VL82CPCAT-16QC/-20QC chipset.

Very fast - runs at 25Mhz, but very picky about RAM quality at this frequency.
Does not cooperate at higher speeds, because it does not provide control over wait states.

The board came with SIPP slots and 4 Mb of 80ns RAM.
I was getting ready for an hour or few of soldering work to swap the SIPP with SIMM slots, but then decided to spin the mobo for a round of early tests and inserted the SIMM slots into the SIPP ones. They snugged so tightly, so i decided to keep them that way.
Soldered fresh battery, crystal oscillator socket and was ready to roll.

The motherboard with 20Mhz Harris CPU, 12Mhz IIT FPU and 4Mb 60ns RAM.

The tests were performed with 25MHz Intersil CPU, 20MHz IIT FPU, 4 Mb 60ns RAM and 0-wait-state ET4000AX VGA with 1Mb RAM.

Metrics are a bit lower than the 286 VLSI motherboard from the first page of this thread.
BIOS seems to be exactly the same, so there are some minor differences in the hardware setup.
For some reason NSSI didn't want to work on this system - reports memory corruption - which may, or may not be indicative of potential instability.
Other than that - everything worked as advertised, as far as i can tell.

benchmark results

Conclusion:
Simply great 286 motherboard - one of the fastest out there.

Migitronics TK-82C491/386-4N-D02C motherboard.
Late model - probably '93 or even '94.
These small format boards are work horses - very stable.
Most of them are not the best performers out there, but this one is actually pretty good.

The board is very unpretentious - takes whatever RAM, SRAM, IDE, VGA get thrown at it.
BIOS is chock-full of options. Things are stable with the lowest possible wait states.
There are options for DLC - verified - works great with CPU upgrades.
These late models don't use crystal oscillators, which makes it pretty much impossible to overclock.
VGA performance is great, but a bit slower than the Symphony mobo.
What really surprised me was the 3D rendering performance - it is the fastest clock-to-clock one i have seen so far.

benchmark results

Great motherboard - fast and reliable.
Most of these late assemblies with 128Kb level 2 cache only are not very good, but this one is different - looking at the offline graphics tests.
The board can clearly do more, but the installed clock generator limits it to 40MHz - too bad.

--- (few years later) ---

ABit AB-AK3 rev.0.2

It looks like the same PCB (with slight differences) has been sold by different brands.
One version has a mixture of 30 and 72 pin SIMM memory slots, but still comes with clock generator.
The other one has crystal oscillator instead of clock generator which makes overclocking possible.
Managed to obtain that second variant not far ago. Wanted to see how it scales past the 40MHz.
Also, at the time i examined the above board i didn't have TI 486SXL2 and IBM BL3 processors.
Sold the board long before getting these CPUs, so that was another point of interest.

It came hard dead.
Took a while to wake it up.
There was a corrosion on one of the BIOS socket pins. Almost invisible on the surface.
There were loose pins on the main CI. Close visual inspection revealed them eventually.
The BIOS chip was damaged. Few bits kept reading wrong, even after multiple reprogramming passes.
Had to take the board through the oven. That took care of unknown number of cold joints.
At the end it lit up, for my great pleasure.

Tested with 2-3 different BIOS versions, including Mr.BIOS.
The fastest BIOS microcodes came from a 486 motherboard based on the same chipset.
Used that for the tests.

--- TI 486SXL2, 45MHz (and 55MHz without FPU, unstable)

System is almost completely stable at 45MHz.
Past that it can work without FPU. Upper limit is 55MHz.
At 50/50 MHz there are L2 cache related instabilities, regardless of BIOS timings.
Tried hard to resolve them by using several sets of trusted L2 cache chips, but apparently the problem is in the motherboard.

All BIOS settings on max with the next exceptions:

45MHz:
AT-BUS CLOCK = 15MHz
for Windows and complex computation tests MEM WAIT STATES = 1 WS (best is 0 WS)

50/55 MHz:
AT-BUS CLOCK = 15MHz
MEM WAIT STATES = 1 WS (best is 0)

Speedsys hangs with SXL2.

benchmark results

The system feels completely stable at 45MHz at everything i tried, but somehow cannot pass the LightWave3D offline graphics test which gives me a pause.
These compact and unpretentious single big chip assemblies have a charm of their own, but UMC's UM82C491F simply does not scale very well to make things interesting.

--- AMD 386DX

Number at 40MHz were shared in the first part of the post.
At 45, 50, 55 MHz the story is exactly like with the SXL2 CPU.
Didn't bother doing in-depth testing.
System is not fully stable at 50/55 MHz.
At 45MHz performance is only marginally higher than the shown 40MHz results.

--- IBM BL3 @90MHz

Shortly after BL3 testing started the board fell silent again. Real bummer. Still trying to figure out where the problem is.
While i don't have captured numbers at this time, performance and stability pattern is like with the SXL2 and 386DX processors.
BL3 pushed things a bit further, but still far below what other motherboards/chipsets can achieve.

---
---
---

The story continues here.

I have captured data for few more 386 motherboards.
Will post it here over time for completeness.

---

ABit AB-FA3 / Lucky Star LS 386DXA, based on ALI-1419 chipset.

Everything started great - pretty agile and nimble mobo. Overclocked to 45Mhz with no problem.
Performed faster than FX-3000 in the basic DOS tests, but then completely failed WinTune2 and the 3D rendering.

Speedsys:

benchmark results

---

Kaimei ALI 386DX / LuckyStar LS-386 ALI, based on ALI-M1429 chipset.

Obviously very late 386 motherboard. Probably 1994. Very stable. Works as advertized. 128Kb cache only.
Does not use crystal oscillator and i don't feel like figuring out if using another clock generator is possible, so capped at 40MHz.

Speedsys:

benchmark results

Didn't want to wait the 2+ hours for the LW3D test. It wouldn't reveal anything surprising - hardware is stable and not very fast.

---

Conclusion:
All in all - average 386 motherboards. Stable, predictable.

Sharing info about two more 386 motherboards.

Biostar MB-1333/40AEA-Q

Neither good or bad board - from the middle of the pack.
Does not overclock at all. Pretty stable. Does what is supposed to do.
Trying to think of anything unique about it but nothing comes to mind.

benchmark results

---

Biostar MB-1340UCQ

Another average representative of the very late 386 class hardware.
Works as advertised.

benchmark results

Didn't run LW3D rendering - takes too long, won't show anything surprising - hardware is stable and performs alight.

---

Conclusion:
Not bad motherboards, very stable, but there are clearly better options out there.

DTK PTM-1632C is an interesting 286 motherboard based on C&T's NEAT chipset.

It allows to combine SIMMs along with on-board memory for maximum amount of 5 Mb RAM.
Cannot remember seeing this in other boards.

BIOS is custom DTK software that was super advanced for 1990 - menus and stuff.
It is very similar to the one of the 386 DTK Symphony boards i stumbled upon not far ago.

The board overclocks pretty well to 27.5 MHz, but requires good quality SIMMs to get there.
With on-board memory chips i was not able to get beyond the 20 MHz. Tried few different 70ms and 80ms sets - but no-go.
So i had to choose between 5 Mb of RAM at 20 MHz, or 4 Mb at 27.5 MHz.
4 Mb of RAM is plenty for 286 hardware, so i went with the higher frequency.

One of the SIMM sockets had its clips chipped-off - replaced it with fresh one.
Didn't have black colored socket, so this section is not color coordinated, but who cares.

The usual set of stats and benchmarks:

benchmark results

Conclusion:
An interesting board, considering its BIOS and memory options.
Overclocks pretty well.
There is no control over wait-states.
Not the fastest piece of 286 hardware.

EDIT:
Updated the first post of this thread with information about two VLB video cards - Diamond Stealth 64 (S3 Trio64) and Paradise (WD90C33-ZZ).