Secret Tech - 8088

Project Briefing
The goal is simply to resurect an 8088 XT computer to its fully working 16 bit, 8 MHz glory. Ok, so its not so simple. The course of the project can be broken into the following steps.

Gather Parts
Parts can be found in many places. Just look for the oldest computer junk you can find. They are often sold on EBay and other online computer surplus outlets. They are found at flea markets and yard sales. The parts gather in basements and attics collecting dust. Sometimes, they are just lying on the side of the road for the garbage man. What to remember when searching for parts is that they are all completly and utterly worthless to just about everyone. Thus, you should not pay hardly anything for parts to an 8088 system. If you are patient enough, you shouldn't even have to order anything.



Remember though, that you need all the essential parts just like in a modern system. That being said, don't stop when you have one of any part. Get multiples of everything. For one, there is no garantee that the parts are the right parts for your system unless you are some kind of guru from that era of computing and can identify every single part by its serial number. Also, the parts may be broken or missing components. Remember to look for parts that still have jumpers and have all of their IC sockets filled. They are more likely to work in that case. Finally, you are likely to break perfectly good parts while building and operating your XT system. You may not know exactly what your doing or you may just make a simple mistake. Applying the wrong jumper and DIP switch settings can sometimes damage hardware. If you were resourceful, then your parts were probably free. If that's the case, its always good to have as much stuff as you can to increase your chances of putting together a working system.

Find Working Hardware
As mentioned before, not all the old computer junk you find will be in working order. If the parts are missing ICs or jumpers, then they are even less likely to work. The resources to fix these problems are hard to find. That is why its good to have several of every part. Now, looking at your pile of old junk, its time to figure out what works. First and foremost, select a motherboard. Bare in mind, motherboards for the XT won't look much like modern boards. The XT has a DIP CPU and math coprocessor and also DRAM which is DIP. They also have DIP ROM chips for bios. You should also see 8 bit ISA slots for inserting various expansion cards. Look for mother boards that have full RAM banks, a chip in the first ROM slot. and are not missing any other chips except for perhaps the 8088 CPU and the 8087 coprocessor. If these are still on the board, then you got a big bonus. If there is a brand clearly printed somewhere on the board, this will likely be handy as well.

Once you find a suitable motherboard, search by its brand online to find information about jumper and DIP settings, how much RAM it can use, and where the 8088 and 8087 go (THIS IS NOT ALWAYS INTUITIVE). If you can't find a brand or other identifying mark on the board, find a database of motherboards that has pictures and search manually. This may take a while but its better than running blind. If you still can't find anything, you can rely on most XT boards to have the same DIP settings and similar jumpers. If you can find one that's similar to your board, you may be able to use it as a reference. If you are lucky, some XT boards have all of these things already labeled, making it very easy.



Now that you have the settings, make sure your board has a PC speaker. If it does not, refer to your settings to find which pins are the speaker output. Pick up a small 8 ohm speaker from Radio Shit and connect it. It is ok to sauter it directly to the pins. Next, check all your jumper and DIP settings and configure them for the lowest settings. This should include however much RAM is on board and no more. Turn off options for expansion RAM. Turn off the coprocessor. Make sure, if your board includes Turbo mode, that it is off. Make certain that you are set for monochrome graphics. Bring it down to one drive. Finally, don't do anything stupid like jump the reset pins or mess with any factory set switch configurations.

Your board should be properly configured for the lowest settings. The board should have its CPU in the proper slot. The BIOS ROM should be present in the first ROM slot. You should have proper RAM. All ISA slots should be clear and the coprocessor should be absent. With all of that setup properly, get a working AT power supply and hook it up. There are power supply testers to make sure a power supply is working. If you have a volt meter, you can get a vague idea but sometimes the supply will read the right voltage but not perform under load. Make sure your power supply is off before attaching it. When attaching the AT supply to the motherboard, make sure that the black ground wires on the conectors are on the inside of the connector strip. Finally, turn on you supply. Allow several seconds for it to start up. If everything is setup and the parts are good, you will hear your board POST through the PC speaker. Once it POSTs cleanly, you know your board, processor, ROM, and RAM all work and its configured properly. Now its just a matter of plugging in parts and seeing if they work. The next things you will need are a serial keyboard, a graphics adapter, CGA monitor, floppy or hardisk controller card, and a floppy or hardisk with bootable media. This will likely be a long and arduous task. Make sure you change your motherboard settings to correspond to any hardware you intend to plug in.

Build an XT


Once you have working parts, you can finally built the XT of your dreams, or by this point, nightmares. You will likely be able to choose from coprocessors, RAM expansion cards, extra parallel ports, multiple floppy drives, 9.6 Kbps modems, SCSI controllers, and many other fun devices. You also need to choose an operating sytem.

Developement History



 * Many parts have been gathered but we still need some crucial things. Namely a floppy controller, and ribbon cable.
 * Our 8088 XT POSTs! However, it seems to be giving us a post code that we can't decipher.  One long beep followed by two short ones.  We were unable to find documentation on our motherboard but we have approximated  the settings since many of the XT boards have standardized settings.  Fortunatly, some of the jumpers were labled as well.
 * We have what we believe to be three working graphics cards. However, they output garbage.  We believe it isn't a problem with the cards but rather the motherboard or the monitor since they all output the same garbage.  We will be invesigating this further.

Applications for XT

 * Parallel Networking
 * LAN MUD
 * Wireless Parallel
 * Token Network
 * Robotics
 * Beer fetching robot