I always liked the DTK 386sx-25 systems due the at form factor
the socketed cpu and various bios timing options, not the best (no sx is)
but quite flexible compared to other sx systems.

I think if I was planning a 386sx build from scratch I'd start with looking for a motherboard with some cache, some had it mounted on the board, some had it inside the motherboard chipset itself, it appears to make a big difference in performance regardless of the actual size, a few K are better than none, so research those chipsets and motherboards to start with.
4MB or RAM is plenty for a 386sx realistically in my opinion, certainly for games, and is fine for playing around with windows 3.1.
As for graphics, a 512k Trident board is probably the smartest choice, cheap(ish), plentiful and fast enough for that level of machine, it also has the advantage of having a simple utility to switch to CGA and Hercules mode and open up your options to play those video standard games too. Also they have no problems with Commander Keen scrolling and other similar issues that other VGA chips may have such as Tseng for example.
As to sound I guess easiest to set up would be a Soundblaster 1, 1.5 or 2, once the hardware jumpers are set your good, it doesn't need any drivers or TSR's. But finding one especially at a reasonable price might be a serious challenge.
I'm sure reading on here about some of the cheaper, easier to find clone cards like the ESS etc would make sense on that score.
You'll want both a 3.5 & 5.25 HD floppy drives if you intend to collect and use original software also, both were used at the time these machines were current.
Personally I'd also be looking for a CRT VGA monitor also, in my humble opinion it makes for a much nicer and more authentic experience. This is of course just a matter of personal taste and preference.
I'm sure other folk here with have different opinions and also give you pointers and advice on mass storage, cases and things like that. I hope you enjoy doing the research and the build itself, and finally welcome to Vogons!

Yeah welcome. Some good tips there. To add to that I'd use a replacement setup for the older smaller IDE hdds that were in use back then. Functioning ones will be hard to come by. CF , DoM or SD based solutions should do the trick.

Getting it networked could be an option as well. Using irc, ftp, telnet and stuff like that.

Caluser2000 wrote on 2020-05-11, 06:29:

Yeah welcome. Some good tips there. To add to that I'd use a replacement setup for the older smaller IDE hdds that were in use back then. Functioning ones will be hard to come by. CF , DoM or SD based solutions should do the trick.

Getting it networked could be an option as well. Using irc, ftp, telnet and stuff like that.

I have some old IDE hard drives in my possession which I can use if they end up working (specifically a late 90s Western Digital Caviar 22500 plus some XP-era 40 GB Maxtor drives), though I will definitely look out for a CompactFlash or SD to IDE adapter just in case.

BSA Starfire wrote on 2020-05-11, 06:14:

I think if I was planning a 386sx build from scratch I'd start with looking for a motherboard with some cache, some had it mount […]
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I think if I was planning a 386sx build from scratch I'd start with looking for a motherboard with some cache, some had it mounted on the board, some had it inside the motherboard chipset itself, it appears to make a big difference in performance regardless of the actual size, a few K are better than none, so research those chipsets and motherboards to start with.
4MB or RAM is plenty for a 386sx realistically in my opinion, certainly for games, and is fine for playing around with windows 3.1.
As for graphics, a 512k Trident board is probably the smartest choice, cheap(ish), plentiful and fast enough for that level of machine, it also has the advantage of having a simple utility to switch to CGA and Hercules mode and open up your options to play those video standard games too. Also they have no problems with Commander Keen scrolling and other similar issues that other VGA chips may have such as Tseng for example.
As to sound I guess easiest to set up would be a Soundblaster 1, 1.5 or 2, once the hardware jumpers are set your good, it doesn't need any drivers or TSR's. But finding one especially at a reasonable price might be a serious challenge.
I'm sure reading on here about some of the cheaper, easier to find clone cards like the ESS etc would make sense on that score.
You'll want both a 3.5 & 5.25 HD floppy drives if you intend to collect and use original software also, both were used at the time these machines were current.
Personally I'd also be looking for a CRT VGA monitor also, in my humble opinion it makes for a much nicer and more authentic experience. This is of course just a matter of personal taste and preference.
I'm sure other folk here with have different opinions and also give you pointers and advice on mass storage, cases and things like that. I hope you enjoy doing the research and the build itself, and finally welcome to Vogons!

So, look for a board with cache, get roughly 4 MB of memory, a Trident VGA card with 512K video memory, a Sound Blaster 1/1.5/2 or compatible clone, both a 3.5" and a 5.25" floppy drive (I already have two 3.5" floppy drives and a box of 100 1.44 MB Maxell 3.5" floppies), a VGA monitor (I don't think I have room for a CRT, and even then I don't think I'd be able to carry one with my noodle arms, sorry), and since I forgot, thanks for the welcomes y'all!

rmay635703 wrote on 2020-05-11, 03:04:

I always liked the DTK 386sx-25 systems due the at form factor
the socketed cpu and various bios timing options, not the best (no sx is)
but quite flexible compared to other sx systems.

I'll have to keep an eye out!

I thought the gains brought by motherboard cache on the 386SX platform were minimal ?

Deksor wrote on 2020-05-11, 14:55:

I thought the gains brought by motherboard cache on the 386SX platform were minimal ?

I don't know, I'm just going off what people who have more knowledge than me on this topic are saying.

I wasn't really saying that for you ^^

Anyways, about 386SX and cache : these boards are rather hard to find, however on the performance thing I only heard that it wasn't that important, but I can't find any benchmark that can confirm this so I'm not sure actually ...
But I think the 16bit bus cached or not is really the bottleneck there. With the tightest timings my 386SX25 will perform similarly to a 386DX25 without cache and I believe that's as far as a 386SX will go.

Now, if anyone can benchmark a 386SX with cache, I'd love to see the results 😁

The original Bios wont handle that sized HDD. You'll have to go the XT-IDE bios route to use it. Either in a nic boot rom socket or dedicated XT-IDE ISA controller card. These are available for using larger cf/sd cards as well.

The original 8-bit Activision Thunderboard sound card would be a good option if you can't get an ISA SB card at a reasonable price. They just lack the midi function which really isn't a big deal anyway.

ashtons wrote on 2020-05-11, 01:56:

I've been planning for some sort of 386SX build for a while. (...) Any recommendations?

Get a cheap mobo with AMD 386SX-40. Or 33MHz if you can't get a 40. Something that doesn't require repairs after battery spill unless you like doing such repairs.
Anything slower than 33MHz might be a problem for some 386-era games, though keep in mind Doom is not going to run well either way (it doesn't even on 386DX 40MHz with cache).

As for mobo with cache... I'd say forget it unless you just happen to find one for a good price. Not worth it otherwise - the whole point of a 386SX was to be cheap by being way less complicated than a "full-fat" 386DX with cache and VLB slots. And I keep repeating this but my own tests show SX mobos (at least the M1217 chipset ones) to be quite good performers if you populate both RAM banks (for interleaving) with fast 60ns (maybe even 70ns will do) sticks and set BIOS to 0WS.

To be fair neither of my 386sx boards have cache, but I have read a few threads here that seem to show a good improvement in memory performance, I think my point was really, knowing they are out there and starting from a blank slate, I'd rather have one with cache than without. But realistically the point about getting a working board without battery damage is the main thing.

ashtons wrote on 2020-05-11, 14:28:

I have some old IDE hard drives in my possession which I can use if they end up working (specifically a late 90s Western Digital Caviar 22500 plus some XP-era 40 GB Maxtor drives), though I will definitely look out for a CompactFlash or SD to IDE adapter just in case.

I think maximum hard drive size that you can usually use by default in such system is about 528MB which is the 1024 cylinder limit, so both of those hard drives are way too large if you don't use any special means to bypass the limit.

I have a a 386SX-40MHz so here is my experience with it, coming from someone who also never used one as a kid (I was born in 1990 - and today is my 30th Birthday bloody nora...)

It's as slow as balls and as a result it's quite a "narrow window" of hardware, and software, to play around with. Generally you'll only have ISA slots and whatever you put in those slots will be CPU limited, in my experience, so you can't really swap out video cards etc as there won't be much gain. You're limited to 'up to' Wolfenstien 3D for gaming, although it is useful having a slow PC like this. Hard drive support will be limited, although CF or SD cards make a great alternative.

For simply messing around with old hardware and stuff, I would suggest a later 486 board, that can take PCI, ISA and VLB cards. This will offer a much, much wider range of hardware and computer speeds to tinker with, from 25MHz to, like, 150MHz? I think?. You can put a slow 25MHz 486SX and pair it with an ISA Trident 9000i for some slow performance, or drop in a 100MHz DX4, 256k cache and a Tseng 6000 PCI video card to get later games working.

Use a busmaster adapter, like SCSI Adaptec 1542.
Use a Tseng ET4000 as graphics card, or a windows accellerator from S3.
RAM is maxed to 16 MB, but there are some chipsets that allow 32 MB (16 MB as EMS then with a driver).
When you run DOS, do not use EMM386. Use an UMB driver that works with your chipset instead.

I've even installed Windows 95 for some testing purposes on my 386SX-20.
However, my Elsa Winner 1000 accellerates Windows in 64K modes but not True Color.