To make a long story short: I have been wanting to build a retro PC around a 486 CPU for some time now, but 486 hardware has really gone up in price in recent years. So I've shied away from it. Last year I started a Socket 7 first gen Pentium build, as a cheaper alternative. But then I finally stumbled upon an auction for a Socket 3 motherboard and decided to pull the trigger. I will still be (separately) working on the other builds.
Although I've purchased some parts already, I will consider this build in the planning phase for now. Input is appreciated. I have a couple of projects I promised for other forum members, and I really need to get those done before I work on anything for myself. I just didn't want to pass up the opportunity to get this hardware. But I figured it would be fun to post this thread now and figure things out, and maybe get some input as well.
The Motherboard: PCChips M912 (https://theretroweb.com/motherboards/s/ ... 2-v1.7-486)
PCChips isn't known for making amazing motherboards, but I don't believe they're as bad as some people make them out to be. They were definitely in the budget category. But since this board still works ~30 years later, I wouldn't say it's inferior quality.
The cons: Nothing is integrated. It basically has some expansion slots and a keyboard port, nothing else. No IDE, floppy, serial, parallel, etc. I'm not sure how common or uncommon those things were during the 486 era. But judging from what I see on the used market in 2023, I would say it was about 50/50 having things like IDE integrated. Also, there's no PCI slots. That seemed to be more of a premium feature for 486 boards. But I figure I still have the Socket 7 build, which has PCI and drive controllers built in. It would be kinda boring to get a motherboard so similar to stuff I already have. This way I get to mess around with controller cards and whatnot.
The pros: It uses a CR2032 CMOS battery. During this time, that wasn't really common. More often you would find those god awful barrel batteries which WILL eventually leak a corrosive juice that will eat away at traces on the motherboard. That kind of damage is usually repairable, and with a simple mod you can use a CR2032, but it's nice that this board is already good to go!
Other thoughts about the motherboard...
This board has VLB expansion slots, which was a sort of stop-gap during the 486 era. I think it would be fun to take advantage of this. There really only seems to be two types of cards worth getting for VLB, a controller card and a video card. I don't know if I would see any real world benefits of a PATA controller card that uses the VLB slot. And to be honest, I don't even know if the types of games I'm looking to play on this machine would even benefit from a VLB video card. But I think it would be cool to get a VLB video card either way, it's just that they're not cheap. On eBay it looks like they're about $50 and up. So I'll have to think about this more. Right now I'm thinking that, after I get this machine up and running, I'll game on an ISA video card and see if I have any problems first. Then I'll get a VLB card if it's actually warranted. But I might want to get a VLB video card anyway, just for the fun of it.
This motherboard can use either 30-pin or 72-pin RAM sticks. Mine came populated with four 30-pin sticks, totaling 4MB. I'll definitely want more RAM in there eventually. I'll probably end up putting 72-pin sticks in there. Although I'm not sure how much yet. It would be easy to just max out the RAM, but where's the fun in that? I'd rather put an amount of RAM in there that's appropriate to the era, but without needlessly handcuffing myself. So I'm thinking 16MB, or maybe 32MB? Is there any difference between using 30 or 72-pin RAM sticks?
This motherboard came with a CPU and HSF, which was another reason it was a good deal. I have a couple of 486 CPUs already, left over from back when I had 486 hardware. But I didn't have the exact CPU I wanted, the DX2 66Mhz. I know that there are faster 486 CPUs, and this motherboard definitely supports the 100Mhz DX4 and probably even a Pentium Overdrive (as well as clones like AMD and Cyrix 5x86). Sometimes it's fun to make a maxed out build, using hardware that was prohibitively expensive when new. But other times I find it more fun to make a modest build, something not only accurate to the era but more likely what you would have had or had been able to afford. I feel like the DX2 66Mhz was the quintessential 486.
I knew that the motherboard included a 66Mhz DX2, but I had no idea if it was going to be Intel or AMD or something else. I didn't really care, but I kinda want the Intel DX2 just for collector's purposes. So when I got the mobo in, I popped the HSF off to take a look, and it is indeed an Intel chip. The only thing though is that it has an X residue of epoxy. I think it must have had a heatsink glued onto it at one point. It looks really clean otherwise. I haven't tried to remove the epoxy yet, but I've read that acetone should do the trick. The included heatsink/fan is the kind that clips onto the CPU, which is exactly what I wanted. I'll definitely want to remove the epoxy, not only to have a nicer looking CPU in my collection (not that I'll ever see it most of the time) but also because I'd like to put thermal paste under the heatsink.
This mobo has a very slight warp to it, but it otherwise looks to be in very good condition. It was impressed with how clean it looks in person (you can't really tell from the eBay pic). Most boards you find are extremely dirty. Either from being in storage, or just a thick layer of dust from being inside a case. This board was well cared for, I suspect a collector had it.
This mobo came with 256K of cache installed. Anyone have any thoughts on this? I may very well leave it, but the board does support 512K or 1MB. I figure once I have the machine up and running, I'll see how the real world performance is. If I have any issues, then I'll think about upgrading the cache.
The case:
Finding good retro PC cases isn't easy. I never see any locally, so my only real avenue is eBay. Retro PC cases are stupid expensive on eBay. So much so, that it's actually cheaper to just buy a fully build 486 PC on eBay rather than trying to build one. And I actually have been window shopping pre-build 486 PCs for this reason. After I purchased this motherboard, I forgot that I'd have to buy a case. But luckily I found a good deal on one. But there's a catch, of course. It's not in the best condition. But that's OK.
I really wanted to get a desktop orientation case for my 486 build. I have many towers already, and I just feel like a desktop is more appropriate for a 486. My family's first PC was a desktop, so I have some nostalgia for it.
I don't find the aethetics of this case to be the most desirable, but I do like it just fine. I really do not like when 3.5" FDD are vertically oriented, but more on that later. On the left side of the front of the case, there's some vertical lines. To me that makes it looks more like it should be in a tower orientation. But I'm hoping once the 5.25" drives are installed it'll look more like a desktop.
It has a keylock and a turbo button, staples of the 486 era! There's no key included for the lock, but I could always get a new lock if desired (I probably wont since I have no reason to lock it). I definitely wanted to get a case with a turbo switch. There's no CPU speed display, which are cool. But I have no nostalgia for them since I never had a PC with one back in the day. But I could actually add one. There's a project I found on Vogons to make your own turbo display. More on that in a bit.
Notice anything missing in the above pic? There's no HDD cage. So as is, there's no way to mount any 3.5" drives. But that's OK! It's one of the reason I got a good deal on this case. As I mentioned, I don't like when 3.5" FDD are vertically oriented. So my plan is to get a 3.5" to 5.25" drive bay adapter. This case has three 5.25" drive bays, which is perfect. I plan to install a CD-ROM drive, a 5.25" FDD, and a 3.5" FDD via an adapter.
But what to do about the empty 3.5" drive bay? Well, I figure I can easily fabricate a cover for that spot, since I don't plan to install any exterior drives in that location. And if I decide to install the turbo display mentioned above, this is exactly where I can install it. So I wont have to cut the case, just the drive bay cover. Which is fine because if I go ahead with the turbo display and later want to remove it, I wont have a hole in the case (I just need to make another 3.5" drive bay cover).
But what about mounting a HDD? Well I haven't figured that one out yet. I was thinking about just getting a CF card adapter, and installing it in an expansion bay slot. Like this:
If I do this, I'll want to get the HDD Clicker. It's a neat little device that adds HDD sounds for those that are use solid state storage devices.
https://www.serdashop.com/HDDClicker
Or if I decide to go with a traditional HDD, I just have to figure out a way to mount it. I figure I could either fabricate my own HDD cage, which would be easy enough since I don't have to worry about it aligning with a front bay opening. Or I could cheat, I've seen random HDD cages on eBay. I could grab one of those, then just hack it to affix it to the inside of the case.
Input wanted on the 5.25" drives! Should I go beige, or black? I have exactly one beige and one black 5.25" FDD. Currently the black one is in my Socket 7 build, but I could remove it and use it for this build. I think the black drives in the beige case makes the PC look older (like old IBMs) which isn't a bad thing in my mind. It's hard to picture what it would look like, I may just have to install both beige and black drives to see. But I think I'm leaning toward putting the black drives in this 486 build, and using beige drives for my Socket 7 build. For reference, here's what my Socket 7 tower currently looks like...
Another reason this case was a bit cheaper than others is because it... has a little patina.
Aside from a really good cleaning, I'll have some rust to remove. I may paint the metal to give it a fresher look. The front plastic isn't too yellow, but I'm undecided what I'm going to do yet. I don't want to Retro Brite something this size. So if I want it to be less yellow, then I may just paint it. And that would be a sure fire way of making sure my fabricated 3.5" drive bay cover matches.
This case also comes with a working AT power supply, but I'm undecided what I'm going to do with it. On one hand, I could refurbish the AT power supply and use it for this build. That is, replace the capacitors and any part that may be warranted to. But the other option would be to just use a new ATX power supply, and that's probably what I'll end up doing.
The only other thing I've purchased so far for this so far is a controller card. And that's really only because I found one new in box at a good price. It's a StarTech brand and seems pretty standard. Two serial, one parallel, one gameport, one FDD and one PATA interface. I really wanted to get a controller card that had two PATA channels, and I still might down the road. I could use one PATA channel for one HDD and one CD-ROM drive, which is all I plan to have in there, but you know how annoying that is with those ribbon cables. So I might use this controller card for the HDD, then use the CD-ROM drive with a sound card. The sound card I plan to use has a PATA interface.
And just in case anyone is wondering, since I have multiple concurrent builds, here's how I plan to use them:
