I will use this thread to document my 486 DX4 100 build. Aiming to closely match the experience and specs of my first ever PC, which was still the only PC our family had until ~ 2001!

I will also be recording the build with the aim to make a little video on it.

The build is also subject to a serious lack of budget but utilizing some bargains and good deals it has cost me relatively little compared to market prices.

The beginning:

It all started with me winning this PC on ebay for ~£25 Delivered:

A nice AT tower case with turbo button and LED display. However the internals of the PC were not matching the era of the case at all. Inside was in fact an AT slot 1 motherboard with a celeron 333mhz and AGP graphics. The system appeared to have been built hastily as many connectors were not plugged in and the MHZ display had its power connections snipped right off.

So I removed the parts inside and was able to sell the motherboard - cpu - ram for the cost of the entire thing. Leaving me with a free case, psu and soundcard (and an S3 trio AGP...) The included hard drive was almost dead and the floppy drive was damaged in transit so I will have to head to my spare parts box for those.

Now for a while I was sat staring at the case with nothing to put in it. I still had retained my DX4 100 CPU but had no motherboard to go with it. I also did not want ISA/VLB based systems as good VGA can get pricey for those, plus my first ever PC was a PCI based 486 and I already had a very close match to my first ever VGA card in my spares box.

So I set out on the hunt for a motherboard. Socket 3 PCI systems do tend to fetch a premium and most of them were well out of my price range for now. That was until I stumbled across a listing from a well known seller on eBay who often charges high prices but for well tested gear. This listing looked perfect for me but was sold untested as the seller was unable to ID the board and therefore unable to set jumpers to actually test it. A quick trip to http://www.win3x.org/uh19/motherboard/search and within 2 minutes I had IDed the board as a PC Chips M918:

A deal was agreed for ~£20! A great price for a motherboard like this so long as it works of course! I eagerly anticipated its delivery..

A few days later it arrived very well packaged as expected and I was able to begin testing, unfortunately after trying all variations of DX4 jumpers and also different flavours of ram the POST card would only ever say 00--, aka brain dead. Next up I started to check what chips were warming up, most of the expected ones were however the cpu was stone cold. As was this bad boy:

Fortunately I remembered my dell 466i has a 5V DX2 fitted. So a late night teardown of that happened to steal the CPU to test my new motherboard:

Success! Out came the multimeter to confirm the death of the transistor and there was continuity between the BASE and COLLECTOR. I am not really sure about transistors but was aware that there should not be continuity so time to remove it and source a new part. Note although I "know" how to solder, my skills are somewhat limited but I had a pretty good success. The pads are all intact and the flux cleaned off nicely.


Note that these pics were taken before cleaning 😀

As per a similar situation in this thread: Running an Am5x86 at 5v? I now also have a BD131 NPN transistor on its way. Which is what I am now waiting for before I can go any further with the build.

I have got the VGA card ready:

2MB S3 virge. I had a 2mb virge in my first PC however it was a diamond stealth (2000?) model. If I see a diamond branded one for cheap I will eventually swap them out.

I also have a small choice for the soundcard. The original system in the case came with this:

Well documented and loved card for DOS/early windows. However my main P3 machine with multi soundcards also has this:

The same but with built in wavetable! I will quite likely go for this card as it is currently in a PC where it competes with an SW60XG for GM duties so is not really ever utilized to its potential.

I will be installing windows 95 as per my original DX4.

The case itself will also need a good restoration as it has some fair rust spots to the rear and a few marks on its shell. Once I figure out the cheapest way to retrobrite I will also be attempting to do that on the plastics.

Thanks for reading 😀