This summer we found a moving sale in our neighborhood. There were a couple of Retro Tech items in the sale, including an Intellivision gaming console. As usual I was wearing one of my retro technology T-Shirts and when I checked out a family member made a comment about their fathers retro tech collection, most of which was still in the basement and had not made it out into the garage yet. I asked if I could have a look and was invited in for a closer look.
He had been working on selling some stuff on eBay, and he had some of the items priced with eBay prices, so I took a pass on most of these items. I let them know that I was willing to repair broken computer and buy bits and pieces and I left with several items and a bunch of pictures. I ended up going back a second time and left with a total of 4-5 boxes full of parts in unknown or untested condition including parts of a 286 PC, Several 5 1/4" Floppy Drives, a 13" Sony Trinitron SVGA display and an Amdek 310A display from around 1985.
The Amdek monitor has been something I'd been looking for for a while as it's a good pair for the Megatel Quark CP/M machine that I've covered previously on the bLog. I'm really glad to have a nice, period correct and crisp monochrome monitor paired with that machine. I'd been running it with a Composite Monitor most recently after having a struggle understanding the video output signal well enough to configure the RGB2HDMI to give a proper display, but that's a story for another day.
The 286 was a longer term project. When I bought it I knew that the battery had leaked, so I was prepared for it to be a lost cause. When I brought the machine home, I took the motherboard out cut the battery off and treated the board with Vinegar in the affected area to try to neutralize the battery acid on the board. After the cleaning (with alcohol) I did try to power up the machine but there were no signs of life. I put the machine away for several weeks.
A couple of weeks ago, a friend of mine got me an ISA / PCI card that displays the POST codes during the PC Boot process. I used this on a couple of "lost cause" boards that I have gotten out of other PCs but I was unsuccessful with the other boards. Then I remembered that this 286 was up on the shelf. The Post card was quite useful in this case because the machine was running enough to return POST codes to the display on the card. The codes were related to Memory. This PC has 2 MB of RAM on board, but it's all in socketed DIP switches. Given the error codes, I pulled all the RAM DIPS and inspected them, then moved them around. I did not want to rule out the idea that there may have been some bad chips, but the error code didn't change, so that seemed to indicate that the RAM DIPS were not the issue.
This early 286 has alot of socketed DIPs, so I went ahead and pulled every other socketed DIP out as well and went through and reseated them. Unfortunately, when I reinstalled them, I had one DIP w/ bent legs, but the POST code changed and I had gotten further along, so I was excited. Once I got the final DIP installed correctly the machine completed booting. Always an exciting moment!
But of course a working main board is just the first part of a build. Although I had rescued many parts from the sale, including the main board, a case, and a 5 1/4" High Density Drive, I did not have most of the rest of the parts I needed to complete the build. Free Geek Twin Cities came to rescue once again. I was able to get a Power Supply, a Disk Controller Card, a Serial and Parallel IO Card, and a low cost Sound Blaster card. I already had an ATI All-In-Wonder VGA / EGA / Hercules card in stock from another project, along with a 1.44MB floppy, and a cool old 200 MB IDE Hard Disk to complete the build. I'm really happy with how the build turned out...
The logic board is labelled as a "Fast" 286, at 10MHz. I know this is nowhere near where the 286 topped out for speed, but I do think it was fast for 1988 so I've made some attempt to keep the build period correct. No Compact Flash drives, although I will not rule that out as a future upgrade.
I've already had a go with Wolfenstein 3D. At this speed, you have to run it in a pretty small window to get acceptable performance, but it's good for Paku and many of course Planet X3 and many of the earlier DOS games. I'm really happy to have a generic 286 in the stable along with a couple of more specialized machines like an HP Vectra 286/12 and the CTP 9000.
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