Best 386 Motherboard?

Discussion about old PC hardware.

Re: Best 386 Motherboard?

Postby Anonymous Coward » 2018-2-17 @ 22:55

Both boards appear to have shortcomings. The top board is interesting because it uses a Forex chipset I've never seen before on a 386 board...single chip. That could be a pretty fast chipset. Unfortunately, the board only has 4 SIMM slots and only up to 128kb L2 cache.
The lower board has many sockets for cache RAM, but unfortunately it only supports the lower density 8kx8 chips, which means a maximum of 128kb. Based on the design of the cache, it's possible that it only accepts 1MB SIMMs too. You won't know until you try.
"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
User avatar
Anonymous Coward
l33t
 
Posts: 3399
Joined: 2008-3-20 @ 05:37
Location: Shandong, China

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-18 @ 00:01

Why would a motherboard manufacturer design a board requiring so many DIP cache modules? Is this cache density configuration a requirement of the chipset?
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby Anonymous Coward » 2018-2-18 @ 10:00

Maybe at one point 8kx8 was the largest available density. Or, maybe the board was a custom job for an OEM trying to get rid of excess supply.
"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
User avatar
Anonymous Coward
l33t
 
Posts: 3399
Joined: 2008-3-20 @ 05:37
Location: Shandong, China

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-18 @ 10:45

So it probably can use more higher density chips? Anyway I am not even sure how to configure it, by default it's working at 25mhz.
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby Skyscraper » 2018-2-18 @ 11:07

The Serpent Rider wrote:So it probably can use more higher density chips? Anyway I am not even sure how to configure it, by default it's working at 25mhz.


You replace the socketed "KOYO" with a faster one to increase the FSB! :)
Main PC: Dual Xeon X5690@4.6ghz, Evga - SR-2, 48gb memory, Intel X25-M g2 SSD and a Nvidia GTX 980 ti.
Retro PC #3: K6-2 450@500mhz, PC-Chips m577, 256mb sdram, AWE64 and a Voodoo Banshee.
Skyscraper
l33t
 
Posts: 3403
Joined: 2013-9-18 @ 15:36
Location: Sweden

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-18 @ 11:09

It's already 66.667mhz.
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby Skyscraper » 2018-2-18 @ 11:10

The Serpent Rider wrote:It's already 66.667mhz.


That is very odd, then it should run at 33 MHz one would think.
Main PC: Dual Xeon X5690@4.6ghz, Evga - SR-2, 48gb memory, Intel X25-M g2 SSD and a Nvidia GTX 980 ti.
Retro PC #3: K6-2 450@500mhz, PC-Chips m577, 256mb sdram, AWE64 and a Voodoo Banshee.
Skyscraper
l33t
 
Posts: 3403
Joined: 2013-9-18 @ 15:36
Location: Sweden

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-18 @ 12:19

Judging by oscillator clock and bios label, this motherboard was produced in early 90s and looks like cash density is not a problem.
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby Skyscraper » 2018-2-22 @ 22:05

This post will be a bit off topic... but still on topic.


I found a dead ISA only OPTI 493 486 motherboard


The corrosion damage. (I'm not the one who has scratched the board)

Corroded tantalum cap.JPG







A Shuttle HOT-403 with a boring AMI BIOS dated the 6th of June 1991 and a non working motherboard with a MR BIOS... This is an opportunity to see if the MR BIOS brings any profit.


Here is a picture showing the two motherboards side by side. Most of the stuff match except for the OPTI F82C206 integrated peripherals controller (where the CMOS lives) versus the UMC UM82C206L. These chips are both copys of the Chips 82C206 from the NEAT AT 286 chipset so any BIOS that works with one should work with the other. Notice the HOT-401s serial number 91-00321. :)

Shotte HOT-403 + dead motherboard.jpg







Well was the MR BIOS still alive? ... yes :)

MR BIOS.jpg







Did it bring any profits? Not much but I could now choose at what rate the memory is beeing refreshed and that did bring a minor improvement.


Above: AMI. Below: MR BIOS. The CPU is a vanilla 486 DX2/66.

HOT-403 AMI + MR BIOS.jpg





I will upload both the 386 and 486 OPTI 391/493 MR BIOS images later. Perhaps they are one and the same, who knows.



Edit

Corrected some faulty information

/Edit
Last edited by Skyscraper on 2018-3-05 @ 18:26, edited 2 times in total.
Main PC: Dual Xeon X5690@4.6ghz, Evga - SR-2, 48gb memory, Intel X25-M g2 SSD and a Nvidia GTX 980 ti.
Retro PC #3: K6-2 450@500mhz, PC-Chips m577, 256mb sdram, AWE64 and a Voodoo Banshee.
Skyscraper
l33t
 
Posts: 3403
Joined: 2013-9-18 @ 15:36
Location: Sweden

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-23 @ 00:54

Could you provide the cachechk v7 memory read and write results? Is your DRAM wait state set to 0 in MR BIOS? Could you provide a screenshot of the MR BIOS chipset, cache, and memory settings?

Using MR BIOS made a fairly generous enhancement on my UMC 481/482 based board. If I recall, the ram read timing went from something like 11 MB/s to 14 MB/s, or about a 30% increase.
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby Skyscraper » 2018-2-23 @ 06:46

feipoa wrote:Could you provide the cachechk v7 memory read and write results? Is your DRAM wait state set to 0 in MR BIOS? Could you provide a screenshot of the MR BIOS chipset, cache, and memory settings?

Using MR BIOS made a fairly generous enhancement on my UMC 481/482 based board. If I recall, the ram read timing went from something like 11 MB/s to 14 MB/s, or about a 30% increase.



I will add a HDD later, then I wll run all sorts of benchmarks. :)


The AMI BIOS for the HOT-403 actually defaults to 0 wait states while the MR BIOS defaults to 0 read 1 write wait states if I remember correctly.

Both the Speedsys results used 0 wait states and pretty much identical settings.

Hidden refresh and slow resfresh were disabled in the AMI BIOS as the HOT-403 didn't like these settings with 8x4MB memory or at least not the "hidden refresh", I don't remember if I tried the "slow refresh" setting by its own. If that setting works I think the MR BIOS loses its performance advantage.

The MR BIOS also had hidden refresh disabled but instead of a "slow refresh" setting it had actual values and the refresh was set to the slowest setting, probably 60us or something like that.

I will post more "screen shots" of the MR BIOS when I get home, I'm at work at the moment.
Last edited by Skyscraper on 2018-2-23 @ 07:04, edited 3 times in total.
Main PC: Dual Xeon X5690@4.6ghz, Evga - SR-2, 48gb memory, Intel X25-M g2 SSD and a Nvidia GTX 980 ti.
Retro PC #3: K6-2 450@500mhz, PC-Chips m577, 256mb sdram, AWE64 and a Voodoo Banshee.
Skyscraper
l33t
 
Posts: 3403
Joined: 2013-9-18 @ 15:36
Location: Sweden

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-23 @ 06:53

On my UMC 481/482 system, MR BIOSes 0 WS for RAM read tested a lot faster than AMI's 0 WS for RAM read.
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby Skyscraper » 2018-2-24 @ 16:00

Here are the requested pictures showing more of the OPTI 493 MR BIOS (486) setup.


These are the default settings (I'm running without a battery and I'm too lazy to change anything except for the HDD and floppy settings if I'm not benching).


MR BIOS setup 2.jpg




MR BIOS setup 3.jpg




MR BIOS setup 4.jpg










This is the OPTI 493 MR BIOS from the 486 board. The dump was made with NSSI. Don't try this BIOS if you don't have a way to recover your old BIOS if it dosn't work.

OPTI 493 i486MRBS.zip
(41.2 KiB) Downloaded 3 times
Last edited by Skyscraper on 2018-3-05 @ 18:29, edited 4 times in total.
Main PC: Dual Xeon X5690@4.6ghz, Evga - SR-2, 48gb memory, Intel X25-M g2 SSD and a Nvidia GTX 980 ti.
Retro PC #3: K6-2 450@500mhz, PC-Chips m577, 256mb sdram, AWE64 and a Voodoo Banshee.
Skyscraper
l33t
 
Posts: 3403
Joined: 2013-9-18 @ 15:36
Location: Sweden

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-24 @ 23:18

Looks similar to the MR BIOS for my UMC 481/482. Yours has a refresh method, which is nice, and an option to set the refresh cycle period. Mine does not and I have to use a DRAM program for DOS to set the refresh period. I find 40 uS is about right. 15 us is typically the default if it is not specified or if there is no option for "slow" or "hidden" refresh.
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-25 @ 20:38

What about PC Chips M326 V5? I found one with integrated AMD 386DX 40mhz. Chipset is CHIP11 9426-ACS / CHIP13, soldered 20ns 128kb cache apparently. Worth a buy?
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-25 @ 20:45

I suppose if you want to restrict your CPU to that of an AMD 386DX and 128 KB cache and the brand doesn't bother you, it might work for your needs/desires. Such a board woulnd't interest me in the least. I wouldn't even accept it for zero cost with free shipping - not worth the loss of storage space.
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-25 @ 20:59

Cache doesn't matter that much after 128k, judging by popular opinion here. Also this board have space for socket, but it's not soldered. Looks similiar to that one, minus CPU socket, board color (green) and few PCB changes to fit soldered CPU: http://www.amoretro.de/wp-content/uploa ... rboard.jpg
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-26 @ 01:08

Depending on the revision of your AMD 386DX, you can completely disable the CPU by setting the FLT# pin to ground. Luckily, the FLT# is next to a GND pin, and you can desolder the FLT# pin and bend it over such that it is touching the GND pin. Turn on your soldering iron and reflow the solder of the GND. Once you float the AMD 386DX, you can solder on a PGA-132 socket and run any CPU. You may not have to do the FLT# to GND solder procedure if your motherboard has a jumper to float the onboard CPU.

It is my personal preference that I like to run 256 K on my PGA-132-containing motherboards and 1024K on my socket3-containing motherboards.
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: Best 386 Motherboard?

Postby The Serpent Rider » 2018-2-26 @ 17:51

And what about "PC Chips" factor?
User avatar
The Serpent Rider
Oldbie
 
Posts: 1786
Joined: 2017-3-25 @ 19:07
Location: Galaxy far, far away

Re: Best 386 Motherboard?

Postby feipoa » 2018-2-26 @ 19:45

May become a collector's brand one day, especially if it has fake cache!
User avatar
feipoa
l33t++
 
Posts: 6778
Joined: 2011-3-07 @ 13:54
Location: Canada

PreviousNext

Return to General Old Hardware

Who is online

Users browsing this forum: aokvilla, derSammler, Oetker, PcBytes, respect2759, stamasd and 17 guests