My 386 time machine project so far

Still working on it, but I made progress and got some pics already!

Project name: "386 time machine project"

Main Project Goal: Build a bare metal DOS machine with as many "recent" parts as possible.

Why? Building with with real 386 hard has a lot of challenges:

- Difficult to find parts
- Often very expensive
- Often not in working condition
- Compatibility issues
- Lack of documentation
- No overclocking / stuck at one speed
- Difficulty using modern gear with it
- AT cases hard to find / ugly
- AT PSUs hard to find / loud / old
- Leaking motherboard batteries
- Could fail anytime
- No IDE and FDD controller on the mainboard
- Leaking motherboard batteries



Project Parts so far:

NEW:

ATX Case
ATX Power Supply
IDE DVDRW
Floppy Drive
2 GB CF Card
CF > IDE converter
PS/2 Keyboard
PS/2 Mouse
S370 cooler

USED (Goal is to use as "recent" items as possible)

S370 mainboard
PIII 800 MHz cpu
128MB SDRAM PC133

Main Challenges found so far:

- It takes a very very fast machine to reach a fast 386 after disabling L1 cache. My estimate is that a 1.3 or 1.4 GHz P III or Celeron in combination with low latency CL2 SDRAM should be able to reach the speed equvalent of a 386DX 25 MHz machine

- Finding S370 boards that support fast cpus (tualatin) AND have ISA slots. My current board only has a single ISA slot. I need a board with 2 (one for Sounblaster, one for Roland MPU401 card). There are models with 2 or 3 slots but they are very rare...










After disabling L1 cache!







Bits and peaces:









Flakey Board

 

and I thought you were just weird wanting to disable L1 cache

Very interesting project! I'm offended you think 386 era machines are ugly, but nevermind. It is hard to find, maintain and have spares for 386 and older machines (I've been collecting for years and have only a couple of worthy 386 boards, and one working 286 board)

it's amazing how much that bench is affected by no cache. Wonder what other benchmarks you could try to get some variation in code.

actually running up wolfenstein or doom and seeing how choppy FPS are would be very interesting!

 

Hey mate, can you change the text colour? Can't be read in sabretooth theme.

Looks like a tops project though

 

Done!

All the cases I found are beige and worn out, full of scratches and changed in colour through sunlight. And the boards are saw cost a fortune, come no extras, no documentation what the jumpers do and then you are stuck at a single speed and need to swap the cpu. With the S370 solution you can play with the FSB (66 / 100 / 133) and get quite a decent range out of the machine. For this P III 800 definitly from a slow 286 to a medium 386.

I have so far found 1 program that doesn't seem to work with the L1 trick and that's the installation program from Wing Commander 2 (where you change the sound settings). However the game works.

A really well written game is Prince of Persia. It runs on my Phenom II off the bootdisk without tweaking. Just like it does on a real 286. Excellent stuff!

Yea without L1 cache this chips are useless... They become very sensitive to memory bandwidth and latency. I don't have any CL2 SDRAM sticks yet, but the Infineons I use handle the timings just fine!

Speed isn't so much the issue, because there is modern hardware that runs perfect with L1 disabled. E.g. my netbook is a perfekt 386DX 20 MHz or something. BUT in DOS without ISA you can't get any sound apart from the PC speaker... There are PCI cards that use drivers in DOS to "fake" interrupts, however they fail when L1 cache is disabled...

Wolfenstein should be playable, I remember playing it on a 386DX 33 and it was very very fast. Doom however will struggle. It really needed a 486 level machine and some of the more intense maps you wanted a DX2 66...

Doom however supports General midi and is a Game I play with windows frontends like Zdoom as I can hook a Roland Sound Canvas into a USB midi port.

The games this project are designed for use sound that is either impossible to emulate (Roland MT-32) or sounds a bit off (DosBOX for FM synth)...

Any game that uses Soundblaster for speech and either MT-32 or Soundcanvas midi can be enjoyed through DosBox without any sacrifices...

However my next project will be comparing the real audio with DosBOX and also looking into how various soundcards compare... So this project will lead to quite a few more!

EDIT: There are many industrial mainboards with P4 and even S775 boards that have ISA slots. They are excellent because (hopefully) you have access to the cpu multi and that way you could emulate any vintage machine really. You could play with the FSB and memory speed. Only problem is they cost like 400 bucks and I was unable to find out if you can even change FSB and multis...

 

Very nice. Always wanted to do something like that. Are you going to drop 98 on it?

 

No plans for W98SE...

Maybe later, but that era wasn't as exciting for me, partly because I went to uni around that time and kinda stopped using computers for a few years. It was all about getting drunk, going clubbing and chasing girls...

A Voodoo 2 SLI system might be on the table, as I did have a Voodoo and Voodoo 2, so that would bring back some nice memories. But the whole Voodoo 3 and Geforce era went past me.

I got back in when the Radeon 9700pro was the latest and greatest...

 

Very nice work. My only suggestion is to find yourself a CRT.

 

If you want the full experience you need to find a case that has a turbo button

Also you might want to find a copy of Xtree GOLD

 

Hehe yea that LCD is only for testing. I will stick with a LCD but will source a 20" 4:3 1600 x 1200 model!

And the MHz LEDs right?

I remember configuring my LEDs once so it would show HI and LO. Took me forever as you had to set a lot of jumpers and the instructions where very cryptic back in the days....

But yea this project isn't about "authenticity", main goal is to use as much new hardware as possible...

I will build a real 486 based on a SX 25 Mhz CPU. I found an adapter from ATX to AT which comes with its own power switch. The mainboard I have my eyes on is very new. PCI slots, all voltages up to 133 MHz support and has IDE and FDD controllers onboard. Just need a PCI video card and I am good to go :-D

 

Yeah those are the ones.. I remember the first time I saw a MHz LED that had 3 digits, my mate turned and said to me "lol what would you ever need 3 digits for".

 

Crazy idea, but you could mount the screen to the side of the case, assuming it was going to be a single unit. Make a custom side panel, so you can run the cables inside and out the PCI covers and have a standalone unit.

 

Memmories..

I have a diamond Monster 3dfx card here somewhere...

Like this.. http://en.wikipedia.org/wiki/File:3dfxvoodoo1diamond.jpg

Cool idea and LOL at Xtree Gold..


MATT

 

Xtree Gold?

 

LOL still quicker than your current rig.

 

Yeah i got one of those too i tried to sell a little while ago here. The winning bidder couldn't be contacted so still sitting in a box if you're interested Mau1wurf1977 let me know.

 

http://en.wikipedia.org/wiki/XTree_Gold

It was quite popular before windows 3.1 (and even during windows 3.1 times)

 

I see! Interesting...

 

Ah, dos... I think we had Quikmenu III back in the day, kind of a windows type environment. Worked really well!

 

Well I love my DOS command line