I picked this beast up quite a while ago, I'm just a bit slow on posting about it. By slow I mean I got it in August 2018.

Here's the tower in all it's glory. It's physically huge, just like it's bigger dual CPU brother.

As it came to me, it was a 486 DX-33, 64 megs ram, BOCA Parallel card, AT&T Starlan (SMC 8013) Ethernet and a Digicom Digichannel C/X serial card. The NCR WaveLan seen was added by me. While I don't have a pic, the front bay devices are a 1.44 meg floppy, 1.2 meg 5.25" floppy and a Sony SDT-5000 DDS drive. No hard drives.

As it sits now, it's a 486 DX2-66, 64 megs ram and all of the above expansions except for the Digicom card. Only other addition is a Quantum 500 meg SCSI hard drive, it'll probably die soon and be replaced with something more reliable.

Let's take a deeper look inside now.

One of the first and most important things I needed to do was fix the NVRAM. This has a Dallas DS1387 that stores the system information. Being an MCA based machine, this is incredibly important to have working, otherwise you get to run the reference disk at every boot. Thankfully being a Dallas NVRAM, it's not hard. Dremel two channels, cut one of the battery connections and solder a holder to the pins.

Another fun thing I did was check out the PSU. It's a 525W(!) proprietary PSU made by MicroEnergy Inc. I have no idea on the specifications for the voltage rails being as it's not marked, but I'd imagine it's a lot. Like 50A 5V or whatnot.

Being as I needed to put the screaming Nidec fan out of its misery, I figured I'd crack it open. One of the first things I seen was RIFA caps. Oh no, these like to go up in smoke and stink up the garage with a burning woodland smell. You can even see the cracks starting to form in them.

Of course I couldn't leave them in place. They aren't quite the same capacitance but they're just mains filter caps, they aren't too important. The main thing is the replacements are the same or higher voltage and safety rated (Class X / Class Y). Easy stuff.

Processor is an Intel 486 DX2-66. The socket above it is for a Weitek 4167 coprocessor. There is no L2 cache in the system, however there looks to have been an adapter board to add support. There's one in a board on ebay but I ain't paying $250 for cache. Unfortunately the system would not work with a Kingston Turbochip. Compatibility with an Overdrive has not been tested - I don't have a 33 FSB one.

So what's it got for disk interfaces? SCSI of course. The factory controller is an NCR 53C700 based controller that connects to a proprietary slot. I'm not sure if it's a PDS of sorts or what - the system ram also connects to the same slots (or at least, very similar). I've got one SCSI card but the system supports a max of two.

The ram is on a card too. It's an adapter board with eight 72 pin simms, all 8 MB sticks. I'm not sure what the max ram supported by the system is. There's 4 slots for ram cards though, however that may not matter with my card. Some other 3434s have 16 meg ram cards with soldered ram. You can see said cards here: https://www.flickr.com/photos/31231773@N02/77 … in/photostream/ .

The video is provided by an NCR 77C22 graphics chip. It looks to have 512K of VRAM?. Unfortunately this thing's an adventure - driver support is very poor. It's got support for DOS, Windows 3.1, OS/2 1.x, OS/2 2.x and Windows NT (provided by MS rather than NCR).

Other goodies: The MCA bus and supporting hardware are 100% NCR custom rolled chips. They didn't just borrow IBM controllers and such to build the systems.

Now that the hardware is covered, let's go over software. The first thing I did was install Windows NT 4

The logical next step was Windows 95. While most of the hardware was supported, the video was not. I was stuck at 640x480 @ 16 colors. The hardware supports 1024x768 @ 256 colors, a huge difference. The Windows 3.1 graphics drivers did not work at all under 95.

The next thing to test was OS/2. There's official OS/2 drivers and even a replacement OS/2 2.1 Disk 1 setup disk (when using CD install)! This was not a success either. I'm running into issues regarding the CD drive. Neither 2.1 or 3.0 will get past the insert CD part. WIth most drives, they just loop there forever. With a specific LaCie/Sanyo drive, it'll just hang on "Loading files from CD". No amount of playing has made it work, however I was able to install NT4 and 95 so I know for sure the drives work. Tomorrow I'm going to play with it some more and maybe just do a floppy install. I'd rather OS/2 over plain DOS + Win 3.1 as that enables OS/2 and Win OS/2. Much more interesting. I could always install NT 3.x but that's incredibly boring.

In summary, this is the NCR System 3434.