VOGONS


Best 386 Motherboard?

Topic actions

Reply 280 of 287, by 386_junkie

User metadata
Rank Oldbie
Rank
Oldbie
luckybob wrote:

That solution wont work in an IBM. Well, as long as you want to use more than 2 simms. Also the board only supports 1MB simms. If I want to use the 5-16mb range, I have to fill one of these: http://minuszerodegrees.net/5162/cards/5162_cards.htm#emea

Your IBM only goes up to 4MB? and what is the FSB of the system? If 20MHz or more, you could get 40ns DRAM to read/write within 1 clock cycle... using 60ns would take 2 clock cycles.

I thought about these ISA bus SIMM extenders before... would they limited to an ISA bus clock divider down to something like 4MHz or would they be remain at the system clock i.e. 16MHz / 20MHz?

Compaq Systempro; EISA Dual 386 ¦ Compaq Junkiepro; EISA Dual 386 ¦ ALR Powerpro; EISA Dual 386

EISA Graphic Cards ¦ EISA Graphic Card Benchmarks

Reply 281 of 287, by The Serpent Rider

User metadata
Rank l33t++
Rank
l33t++

If 20MHz or more, you could get 40ns DRAM to read/write within 1 clock cycle... using 60ns would take 2 clock cycles.

Aren't any memory with 70ns or less is way out of specs for 386 and should work too?

I must be some kind of standard: the anonymous gangbanger of the 21st century.

Reply 282 of 287, by The Serpent Rider

User metadata
Rank l33t++
Rank
l33t++

Soo... acquired the best (tm) motherboard for 386DX I could find. VLB, 256kb Cache, Cyrix 486 support, etc. Well, almost: sockets for 386 CPU/FPU are not soldered, but apparently my version of Dataexpert EXP4349 board is lacking only in that department. All jumpers from online manuals appears to be present. So all I need to do is to add those sockets, right? Or I'm missing something?

Dataexpert EXP4349 - A.jpg
Filename
Dataexpert EXP4349 - A.jpg
File size
1.08 MiB
Views
849 views
File license
Fair use/fair dealing exception
Dataexpert EXP4349 - B.jpg
Filename
Dataexpert EXP4349 - B.jpg
File size
688.99 KiB
Views
849 views
File license
Fair use/fair dealing exception
Dataexpert EXP4349 - C.jpg
Filename
Dataexpert EXP4349 - C.jpg
File size
844.62 KiB
Views
849 views
File license
Fair use/fair dealing exception

Also I'm confused with 3.3v option for CPU without voltage regulator present on the board (jumpers 50, 51, 52).

Last edited by The Serpent Rider on 2018-05-27, 02:46. Edited 1 time in total.

I must be some kind of standard: the anonymous gangbanger of the 21st century.

Reply 283 of 287, by feipoa

User metadata
Rank l33t++
Rank
l33t++

It probably doesn't have a 3.3 V option without the voltage regulator, so set the jumpers for 5 V.

In all liklihood, soldering in the 386 and FPU sockets will allow you to use 386 CPUs. Aside from the missing voltage regulator, are there many missing components?

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

Reply 284 of 287, by The Serpent Rider

User metadata
Rank l33t++
Rank
l33t++

I am not sure where voltage regulator could be installed on this board.

Dataexpert EXP4349 possible VR place.jpg
Filename
Dataexpert EXP4349 possible VR place.jpg
File size
323.49 KiB
Views
832 views
File license
Fair use/fair dealing exception

Maybe here vertically?

Aside from the missing voltage regulator, are there many missing components?

That's what I want to know from the other owners. Jumpers are safe, components seems to be safe too, judging by this pics: https://imgur.com/a/sZPMB

I must be some kind of standard: the anonymous gangbanger of the 21st century.

Reply 285 of 287, by feipoa

User metadata
Rank l33t++
Rank
l33t++

Yes, that is the spot which I would guess the voltage regulator IC goes. What I find further interesting about those photos on imgur is the sticker "This PGA socket is intended for TI486SXL Microprocessor only". I've never seen such a sticker on a motherboard. I'm guessing that certain jumpers were soldered on for the SXL pinout, which has some minor differences with the i486SX pinout, yet, an SX CPU is installed.

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

Reply 286 of 287, by God Of Gaming

User metadata
Rank Member
Rank
Member

Took a quick look for any local 386dx40 mobo listings, and found two:

This unknown model with Opti chipset and soldered cpu (no big deal, its dx40)

37xl1lq.jpg

And this ROBOTECH GMB-386UN with a... Toshiba chipset it says?

LP4MwRZ.jpg

Is one of these two any good and worth adding to my collection?

1999 Dream PC project | DirectX 8 PC project | 2003 Dream PC project

Reply 287 of 287, by dj_pirtu

User metadata
Rank Member
Rank
Member

Got myself a MG-38606 REV 2 motherboard with UMC48x. Flashed MR BIOS and got lots of BIOS settings to tinker with.
There's 486DLC-33 and I've been overclocking it to 40, 45 and 50MHZ.

Motherboard takes FSB to 50MHz but after few minutes it'll start crashing. If I put 120mm fan to blow on to motherboard it works. Still need to hunt that chip which will need that kind of cooling among CPU.
I have 16MB 60ns RAM and 1WS is needed 45MHz upwards. 256KB cache works with 0WS.