Rescuing a 286 from the housing estate

Every now and then something happens that delights any lover of old hardware. Exactly such a moment came this winter when I was walking home through the housing estate. Next to an e-waste container I noticed an old computer case. At first glance it was obvious that it was nothing modern – rather a piece of history from the days when computers were only beginning to find their way into homes. At moments like this, any embarrassment goes out the window. I certainly wasn’t going to leave it lying there.

First impression: a 286 or a 386?

Judging by its appearance, it was a genuinely old machine. A sturdy sheet-metal case, classic AT format and typical front panels. At that moment I guessed it came from the 286/386 era. You don’t come across machines like this very often today – let alone find one lying next to a rubbish container. It didn’t take long to decide. Of course the computer came home with me. I carried it in my arms for about 2 km. Even in the winter I worked up quite a sweat, but what wouldn’t I sacrifice for something this beautiful?

Opening it for the first time: surprises and missing parts

Opening the case brought the first surprise – the computer wasn’t complete. The graphics card was missing, as was the disk controller. With a machine this old that is a serious problem, because without the controller the hard drive is practically unusable. All the more valuable was the fact that the motherboard and hard drive were still inside. What’s more, it was an MFM drive, the predecessor of IDE drives. That gave me a good foundation to build on. Unfortunately, the battery on the motherboard had already done its damage, so the board came out. I neutralised the area around the battery, cleaned it carefully and fitted a BezVarta replacement.

Identification: a genuine 286

A closer inspection made it clear – this really is a classic 286. Inside was a Seagate ST-225 hard drive with a capacity of 20 MB, which was absolutely standard in its day. This model had a reputation as a quality drive, so I hoped it might still work after all these years. There was also a 5.25″ NEC floppy drive, an inseparable part of the era in which this computer was built.

Another interesting detail is the sticker on the back of the case, featuring a globe logo and the designation NTS,
which probably points to the origin or distributor of this particular machine.

Power supply: the toughest nut to crack

A major problem appeared with the power supply. After the first attempt to switch it on, it was obvious that the PSU was completely dead – no response, no voltage, absolute silence. At first I tried repairing it myself. I replaced several capacitors, a common source of trouble in old power supplies, as well as two Schottky diodes on the input. Unfortunately, even after these interventions the PSU still showed no signs of life.

At that point it was clear that the fault was more complicated. I therefore entrusted the power supply to an experienced electronics technician. He spent many hours on the repair and has my full admiration. He worked systematically, measuring the individual sections step by step and gradually replacing a number of components until he finally managed to bring the PSU back to life. Incredible – and many thanks for being willing to take it on. Borek really is a star.

Hunting for an MFM controller: a little detective story

Because I had practically no previous experience with MFM drives, a little investigation began. Unlike IDE drives, MFM drives use two cables and require a specific controller. In the end I managed to find a suitable MFM controller in Germany. The seller was very helpful – not only did he offer it at a reasonable price, he also added small extras such as blanking plates and other accessories to the parcel. Details like that always make me happy and give me an appetite for more projects like this.

I didn’t have to hunt for a graphics card – I reached into my own stock and used a Trident 9000, a very period-appropriate solution for this kind of system.

Experimenting with cables: a dead end with an FDD cable

One of the most interesting parts of bringing the machine back to life came when I was working out how to connect the hard drive. MFM drives use two separate cables – one for data and one for control – which is a completely different approach from what I was used to with IDE and newer interfaces. On my first attempt, however, I made a classic beginner’s mistake: I used a floppy-drive (FDD) cable. It has the typical twist in its conductors, used to distinguish drives A: and B:. The result was predictable – the disk behaved incorrectly and the system didn’t work. Fortunately, I identified the mistake with a friend helping me over the phone. In the end I opted for a somewhat radical solution. I removed the twisted section of the cable completely and used only the straight section without the twist. It was actually unavoidable because the rear of the computer is very cramped due to the large power supply.

And that was the turning point – the disk immediately came to life, began communicating normally and the whole system sprang into action. There was therefore no need at all to perform a Low Level Format, which is often considered one of the first steps with MFM drives. In this case the problem was purely the cabling and my initial lack of experience. It is a nice example of how even a seemingly minor detail can determine whether old hardware works or not. I was especially pleased by the LED on the front panel that indicates disk activity. All I had to do was find the correct pin on the controller and attach the corresponding cable and connector from the front panel.

Trouble with a black-and-white picture

The first connection brought a small disappointment – the image on a modern LCD monitor was only black and white. The reason is relatively simple, though. Old VGA cards and even older systems often worked with different signal synchronisation methods, and some modern monitors cannot handle them correctly. Older hardware could also be configured for monochrome output. But after connecting the computer to a classic CRT monitor everything changed immediately – the picture is beautifully colourful and exactly as it should be.

The basics work – what next?

I really enjoyed the whole project. Waiting for the MFM disk or pestering someone to repair the old power supply took time, but the feeling when it suddenly boots is always indescribable 🙂 The computer that ended up next to a rubbish container is working again today and recalls a time when 20 MB of disk space felt enormous and every expansion was a small adventure. Incidentally, the disk contained the graphics program Banner Mania, which brings back some nice childhood memories for me. Perhaps that was where the seeds of my later interest in graphics and web design were planted 🙂 That is the nicest thing about retro computing – it is not just about hardware, but also about stories and memories that come back to life with it.

I still plan to revive the 5.25″ drive. It does show signs of life, but it doesn’t read disks and makes a strange, rather rough sound. It would certainly be better to use one with a matching colour, because this particular drive is black. I’m also considering a complete restoration of the entire sheet-metal case. Then the whole computer really will be a display piece.