How to Build a Computer

Cases Come In A Wide Variety Of Shapes And Sizes

Before spending a cent, investigate the vendor! That engraved business card, offered by a friendly hand at a computer show, might read INTER-GALACTIC ELECTRONICS -- INTERNET SERVICE PROVIDERS & SATELLITE ENGINEERS. A day or so later, in a panic upon finding that none of your "bargains" work, you attempt to call the tech support number listed on the card. A voice answers, "BAIT SHOP." You hang up and try again. The same voice, a little annoyed, "BAIT SHOP!" You, after hesitating a bit, ask for "Lem" -- that nice dealer at the show. "Lem? My cousin Lem? He don't work here no more!" And then hangs up. Your last three meals start to sink towards the floor.

Variations on this theme are the continuously busy phone and the disconnected phone.

Part with your money only if you're sure that you can find the seller later.

If a part that is regularly $100 is being sold for $2, heck, you might feel lucky. If the reverse is the case, a $100 part is going for $98, cash only, start thinking about the old risk/reward ratio.

The safest route is to pay by credit card. In case of a DOA part, just cancel the charge.

Most dealers at Computer Show and over the Internet are honest, but it is very easy for the wolf to don sheep's clothing. If the seller requires cash, or, as I saw in a net ad, a postal money order , with the PAY TO name left blank, to be sent to "AK47 GENERAL DELIVERY", it might not hurt to ponder why the transaction needs to be carried out in this manner.

There are times when bargains are carried out on a cash basis. It is also possible that the dealer does not accept credit cards in order to hold down overhead. I've seen good shops, when deciding to clear out old parts, sell the stuff cash and carry. They honestly report if the part works. In any event, the price is so cheap that little risk is taken. If the part is sold as functional, it gets a NO DOA guarantee. For transactions conducted through the mail, there should be no hesitation on giving you their physical address and phone number. You should expect to wait for your check to clear before the seller ships the part.

Auctions are another hotbed of fraud. People have bid on shrink-wrapped boxes, assuming that the goods were new. Upon accepting the lot (after paying for it), it turns out the material is used or simply not in working order. Systems turn out to lack motherboards and memory. The imagination of con artists works day and night! You can find bargains at auctions, but don't forget that you are, in essence, gambling. If you go to these venues with the same attitude that you would take on a trip to Las Vegas, great!

No matter where you buy, be certain that you understand the guarantee and return policy. "ONE YEAR GUARANTEE" sounds great but is pretty shabby if you've got to send the part half-way around the World to get a replacement. "Look who it's made by" ain't no guarantee. Many manufacturers of hard drives, for example, OEM whole lines. This means that they don't take returns of those items, no matter how "right from the factory" it is. If the part is not in a computer bought new, then it's grey-market. If it was in a system, as intended, in that case the various distribution channels for the computer system manufacturer would handle the return process. You didn't buy a new machine? You're on your own!

You might be tempted to deal right to the bone to save every last penny. You buy your hard drive from "Sam's House of Hard Drives." The CPU comes from "Wally's Processor Heaven." The motherboard comes from "Joe's One Thousand and One Boards." And the deal you get when you buy your SIMMs at "Lee's Thank You For The Memories." The money you saved! But, nothing works! Sam tells you, "That double Gig could hold up a house! Your memory stinks!" Wally confides, "Sam's hard drives are only compatible with boards built in Antarctica during the rainy season." Joe is irate, "I TESTED THAT BOARD PERSONALLY. WE DON'T REPLACE THINGS RUINED BY BAD PROCESSORS!" Lee queries, Check the power supply? It's plugged in? Are the street lights lit? Are you sure it's not the Window's drivers?" Buy the backbone of your system from one place. Stay off of the merry-go-round!

If by now you have not run off in fright, let's figure out what you need! In any event you're going to be buying a motherboard. You're most often better off buying one with the processor (CPU chip) already installed. If the price of the board seems fantastically low, make sure that the processor is included.

PCI PENTIUM Motherboard With CPU Installed

For the memory, seventy-two pin SIMMS are now standard. The only reason for getting a motherboard with 30 pin SIMM slots is if you want to get by with the memory that you have on hand.

As for the bus architecture, PCI rules. Don't buy a VLB or an EISA motherboard unless you've got a drawer full of VLB or EISA interface cards gathering dust. Combination motherboards (e.g. ones that take both VLB and PCI cards) suffer from compromised performance. PCI main boards as a matter of course take the standard 8 and 16 bit cards (ISA), plus the state-of-the-art PCI option boards. PCI is the best bet for WINDOWS 95's PLUG AND PLAY. Everything else is legacy.

30 and 72 Pin SIMM Chips

A Solid Mid-Tower Case Will Provide A Good Foundation For A Homebuilt PC
For the RAM (SIMM chips) don't take any slower than 70ns. Faster (e.g. 60 ns) is great, but be ready to pay the premium price. With the 72 pin chips, PENTIUMs need them in pairs, while 486s use one chip at a time. Be sure that you know how many slots that you have on your motherboard. For a PENTIUM system with two slots, if you start of with 8 megs (two, 4 meg, 72 pin SIMMS), in order to go to 16 megs, you will have to remove the existing memory. This is pretty easy, but there will be little cash value for the 4 meg chips. The 30 pin SIMMS are installed either in pairs or groups of four, depending on the board design. Again, know the total number of slots before you buy.

When handling ANY circuitry, particularly motherboards and RAM, make sure that you are not carrying a static charge. Jolting them results in death by electrocution, for the part that is! Special grounded pads are available. Grounded wrist belts are also sold. At the very least, touch some relatively large metal object before you pick up any components. Try to handle the board by the fibreglass, not the metal. Work on a non-conductive surface. ALWAYS MAKE SURE THAT THE POWER IS OFF BEFORE INSTALLING OR REMOVING ANY COMPONENTS! Don't just turn it off, it's too easy to hit the switch by mistake! PULL THE PLUG!

The Pins On A PENTIUM Are Angled At One Corner. This Matches A Similar Slanted Row Of Holes In The CPU Socket. Lined Up Properly, The CPU Will Fall Right In. DO NOT Use Any Force! You Will Bend The Delicate Pins And Very Likely Ruin The Chip!

A ZIF (Zero Insertion Force) Socket. With The Handle Up, The CPU Pops In. Once Handle Is Lowered And Latched, The Chips Is Fastened Securely Into Place.

It's a good idea, especially if you plan on crafting a number of systems, to have a spare power supply. This way you can test the motherboard without installing it in the case. Sad to relate, new motherboards, particularly the cheaper ones, are VERY often defective. If it turns out that you've got a bum board, the initial test saves you all the trouble of playing with the standoffs and the screws.

A good used 150 watt power supply should go for about $10. Power supplies made by the Korean and Japanese manufacturers often use a non-standard clip. An exacto razor blade trims the plastic easily. These power supplies can then be used for bench testing.

Power Supply Connectors Installed On The Motherboard.
Make Sure That The Black Wires Meet In The Middle!/
The Connectors For The Other Devices Will Only Go In One Way.
Write this on your mirror so that you can see it while you are shaving (for women, geez, I don't know, why don't any of the memory mastery courses say what to do!). Write it in small letters on your wrist watch. Repeat it while waiting in lines. For the power supply wires to the motherboard, the black wires meet in the middle. IF YOU PUT IT ON BACKWARDS YOUR BOARD WILL FRY! Just get in the habit of constantly checking yourself. Before you connect the power cord, check it again. You don't want to see the black wires on opposite ends of the power connectors to the motherboard. The pins on the motherboard for the power supply can be delicate. Be careful with them. Sometimes the connection is tight and you might have to shimmy it into place. Take it slow. The power cords to the drives will only fit in one way.

If the ON/OFF switch needs to be installed, take care. Look on the back of the switch. You'll see a raised ridge of plastic dividing the connectors into two groups. The blue and white wires go on one side of the ridge;the brown and black go on the other. What matters is just that the two sets of colors are kept apart. Top, bottom, right, or left does not make any difference. If the power supply, as most newer ones do, uses two white wires and two black wires, then the white both go on one side. Of course, then the two black wires get installed on the other side. Mistakes in wiring the power switch are usually not pyrotechnic. The system will not work, or the house circuit breaker or fuse will blow. With crossed wires, ya ain't gonna be the first on your block to install QUAKE!
Correct Installation Of Wires To The ON/OFF Switch
The Fifth Black Wire Looping To The Left Is A Ground Wire. Screw It Any Metal Part Of The Case. DO NOT Attach The Ground Wire To A Screw Hole Of A Drive!

For a board to try to come to life, the RAM and the video card need to be installed. For your power supply to do its thing it must be connected to the motherboard (properly as stressed above) and to one drive. The drive need not (for testing's sake) actually be connected by a cable to an interface card or set of pins on the motherboard. It just needs to be plugged in to the power supply in order to provide a load.

Carefully insert your SIMM chips into the motherboard. There is a #1 SIMM slot, most often labeled 0, a #2, most often labeled 1, and so on. The SIMM chips need to be inserted in the proper order. Make sure that you've got it right. Gently insert the RAM and push up slowly until it clicks into place. Double check that it is in evenly. Bad contacts at the SIMM chips is the primary cause of a motherboard failing to fire up. Insert your display adapter. Attach the monitor.

CPU Cooling Fan
Just about all modern processors require a cooling fan. This is a miniature electric fan that snaps onto the CPU. Without one the system will intermittently fail. Permanent damage to the CPU is possible. The cooling fan uses one of the connectors from the power supply, but the fan generally has a power socket so that a device can be plugged into it, daisy-chain fashion. I suggest, if possible, to not use the CPU cooling fan connector. I've suspected that electical noise from this little motor to be the cause of sporadic system failures. If you've got to plug something into the same line as the CPU cooling fan, use it for something besides the hard drive.

You've got the motherboard on a non-conductive surface. Check again that the power supply wires are properly connected on the motherboard. Turn on the electricity. If you hear ANY CRACKLING NOISE, SEE OR SMELL ANY SMOKE, THEN PULL THE PLUG IMMEDIATELY! My worst experience with a defective power supply sent foot long sparks emanating from the motherboard. The florescent lights in the shop (which were turned off) lit up.

If all goes well the POST (Power On Self Test) will start on the screen. This will lead to a message prompting you to enter SETUP. Just turn everything off, for now.

If, instead, nothing happens, turn off the power. Make sure that the RAM is making good contact and that it is in the proper slots. Make sure that the video card is completely inserted and that all the chips on the video card are in all the way. Same for the ROM chips on the motherboard. If you still get nothing, time to call to arrange for a return.

Plastic Stand-Off

If everything went ok, you can now install the motherboard in the case. Cover the screw holes in the case (the ones that are used to secure the motherboard to the base) with non-conductive electrician's tape. Place the plastic standoffs in the slots in the base of the case. Position the motherboard over the standoffs. Firmly but gently press the motherboard into place. Check to see if the keyboard connector is properly aligned with its hole. If not, wiggle the board until it is in place. Put cardboard washers over the screw holes. Using the screws, anchor the board. Don't get carried away and punch a hole in it!
Brass Stand-Off For Securing The Motherboard To The Case

You will see pins for the TURBO switch on the motherboard. Find out if your system needs these pins open or closed in order to run in fast (TURBO) mode. Don't bother connecting the switch. If you need them closed, jumper them closed permanently. If open, then just leave the pins open. Buying as fast a system as you can afford and then installing a "slow" switch, makes no sense to me!

Now install the wires for the SPEAKER, RESET, POWER LED, KEYBOARD LOCK, and TURBO LED. Very often, the wires for the TURBO LED don't match the pins on the motherboard. Don't worry about it. Make sure that you don't connect the wrong wires to the pins for RESET. This will (temporarily) knock the system out.

If the POWER and the HARD DRIVE LEDs don't light, then you've connected those wires incorrectly. Turn the system off and adjust the leads. There are specific positive and negative pins, so you might have to rotate the little plug. This will be glaringly evident in the case of the KEYLOCK. If you install it backwards the system will start up with a KEYBOARD ERROR or KEYBOARD LOCKED message. An infinite number of monkeys can then spend eternity banging on the keyboard and still not be able to produce the Bible! Just orient the contacts the right way and all will be well. Again, check that the power supply is correctly attached to the motherboard. For starters insert only the video card. Install the floppy drive into the case. Plug the power supply into the floppy drive. Turn on the computer. Again, if ANYTHING seems wrong, turn everything off!

If the system goes into POST, hit RESET, just to make sure that you've got the wires plugged in the right way. Check that the POWER LED is lit. Try out the lock. If anything is screwy, turn the system off and reposition the wires.

1.44 Meg Floppy Drive. Still The Standard On Most Systems

Floppy Drive Cable. The Connector With The Twisted Wires is Used For the A Drive

Now, with the power off, install your hard drive and the interface card for your hard drive and floppy drive. Turn the system back on. Go into SETUP. You will have to set the TIME, DATE, and define your floppy drive. If you have a SCSI hard drive, leave drive C as NOT INSTALLED. If you've got an IDE drive, most (maybe all?) new motherboards will automatically detect and configure for your hard drive.

Since your new hard drive will probably be bigger than 528 meg , unless the BIOS on your board supports these drives, you will need to run a hard drive SETUP disk from the drive manufacturer in order to partition and format the drive. If your BIOS is compatible with large IDE drives, just use the DOS FDISK and FORMAT commands.
IDE Hard Drive And 40 Pin Cable. The Red Line On The Cable Indicates Pin 1. Point This Red Line Towards The Power Connector On The Hard Drive. The Red Line Is Oriented Towards Pin 1 On The IDE Pins On The Motherboard Or Adapter.

SCSI adapters contain their own BIOS that supports the large SCSI hard drives.