Build your Own PC Part 1- know how to Do it yourself

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Connecting The Floppy Drives

Floppy drives are in danger of extinction because floppies generally don't hold much data. Most software is generally installed from CD-ROMs now, anyway. CD burners are very popular for archiving data. Nevertheless, a floppy drive can still pay off if you work with old programs or data from time to time.

Floppy connector (34-pin) above, IDE connector(40-pin) for hard drives and CD-ROM below.

It's easy to spot floppy cables. They usually have a "twist" of individual wires, as you can see in the upper corner of the image. The image shows a color marking on a cable. This is frequently a red line that marks pin 1. Pin 1 is also printed on the motherboard. On modern motherboards, notches and/ or a missing pin in the middle (see picture blow) prevent the cable from being inserted the wrong way. You still need to watch out when hooking up older drives or motherboards. The red dotted line at the other end of the cable should always point in the direction of the power supply. Here, too, there is a reverse-connection protection to keep it from being improperly configured.

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Connecting Hard Drives And CD-ROM/DVD

The vast majority of hard drives and CD/DVD drives are based on the IDE (Integrated Device Electronics) standard. There's also the SCSI standard, which is mostly used for servers or workstations. In comparison to SCSI, IDE is extremely cheap to produce, which accounts for its higher popularity. There are four subgroups within the IDE class: UltraDMA/33; UltraDMA/66; UltraDMA/100; and UltraDMA/133. The number at the end describes its bandwidth. As a rule of thumb, the higher, the better. 133, for example, stands for the maximum data transfer rate of 133 megaBytes per second. DMA is short for Direct Memory Access. A beginner doesn't necessarily have to know how DMA works in order to obtain good results.
Two drives can be run on each IDE connector block. Motherboards usually have two IDE connectors (Primary and Secondary IDE), so that a maximum of four devices can be connected. Modern motherboards with an additional controller can even offer four IDE connectors. If you want to connect an IDE to a drive, it is configured as a "Master" (Single). If, on the other hand, two drives need to be connected, one must be labeled "Master," and the other "Slave." The jumpers are used to connect the contacts, thus configuring the drive. The connection to the motherboard is made by way of a 40-pin ribbon cable. It has three plugs - one for the motherboard, and the other two for the two drives.
Most PC systems have one hard drive and one CD-ROM/DVD drive. CD-ROM burners are also a type of CD-ROM drive. The following configuration is recommended for IDE drives:

• Primary IDE: hard drive as Master (Single) Primary IDE:
• Secondary IDE: CD/DVD drive as Master (Single)

Users who want the full allotment of IDE components should connect the drives as follows:

• Primary IDE: hard drive 1 as Master (Dual)
• Primary IDE: hard drive 2 as Slave (Dual)
• Secondary IDE: CD/DVD drive 1 as Master (Dual)
• Secondary IDE: CD/DVD drive 2 as Slave (Dual)

There's usually a sticker on top of the drive explaining the necessary jumper settings. Or, you can also find a description in the hard drive manual.



IDE jumper table for a Maxtor hard drive.




Port panel on the hard drive: power supply, jumper blocks, IDE ribbon cable (from left to right).

Connecting the CD and/ or DVD drives is basically the same as with hard drives. The same rules apply.



CD-ROM port panel: digital audio, analog audio, jumper blocks, IDE cable, power supply (from left to right).

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SCSI Drives - The Exception

Although the SCSI (Small Computer Systems Interface) bus system offers greater flexibility, it's also much more expensive. SCSI is only used for workstations and servers. Ultra2 or Ultra 160 SCSIs are typical standards. A SCSI ribbon cable has 68 pins. All SCSI standards have one thing in common: you can run at least seven drives on one adapter. "Wide" models even allow 14 devices to be operated.
It is important to know how it works. SCSI is an open bus system and allows cable lengths of well over a meter. However, the bus must be closed with a terminal resistor at each end, so that the signals don't reflect. Termination can mostly be activated by a jumper on the last device. LVD cables have their terminator as a plug-on module. The position of the individual devices on the SCSI cable, by the way, is up to you. The drives are distinguished by way of so-called SCSI Ids that run from 0 to 7 or 0 to 15. ID7 is usually the host adapter, 0 or 1 is usually used for the hard drive(s). The rest of the configuration is up to you. Jumpers are used to define the ID address from 0 to 7. In the following example, the manufacturer has named its SCSI address IDs DAS0 to DAS3.

Description of the SCSI jumper block for auxiliary connectors. DAS0 to DAS3 are the SCSI address bits.


Jumper table for setting addresses.




Connector blocks on an SCSI hard drive: power supply, jumper blocks (auxiliary connector), SCSI ribbon cable (from left to right).

In this example, termination can be activated by bridging pins 9 and 10. This is called "Enable SE SCSI Terminator" in the picture.

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Safety Notice: The Destructive Potential Of Electrostatic

Walking across a floor dragging your feet will create friction, which charges us with energy. Once you stop moving, the soles of your shoes insulate you, but you're still carrying around a different voltage potential than your environment. Everyone's felt the sudden shock from a static spark, which is particularly common with plastic floors and thick, rubber-soled shoes. This electromagnetic phenomenon can have dangerous consequences for electronic components. Although the current from a static discharge isn't very high, the voltage difference may briefly peak at tens of thousands of volts. That much voltage can easily destroy sensitive components such as memory chips.
The most important thing to do before getting down to work is to ground yourself. Ideally, you'll have an antistatic armband, as used in industry. But unless you're a real electronics whiz, you're unlikely to have one. So, try this instead: before you come into contact any of your PC's components, simply touch something metal (a radiator, the protective contact on a plug or the PC case). This will ground you properly.
Drawing Up A Plan

Before you start the actual assembly, familiarize yourself with the case and components. Unpack all the parts and keep them nearby, but not so close that they interfere. Most cases don't come with instructions, so you should first check which screws and parts go where, and what each is for - and whether you may have to remove anything from the case before you can install the drives. Get yourself a proper lamp before starting, especially if you work at night. The ceiling light in your workroom is usually not bright enough.
Finally, consider where you want to put each drive. There are only a few rules for drive placement, but valuable ones to follow when in doubt:

• If the PC is under your desk, it makes sense to place the CD-ROM and/or DVD drive as high up as possible so that you don't have to bend down so far.
• Always check to make sure that the ribbon cable is long enough.
• Some components get warm or even hot when operating. Always make sure that there's enough air circulating for the heat to dissipate. That's especially important for modern graphics cards and hard drives.
• If you're intending to put in two hard drives, make sure that there's enough room between them. Otherwise, they may overheat, leading to a shortened life span and instability.
• Make sure that neither cables nor other components can get caught in a fan.
• All cables must be run so that no air vents or openings are completely blocked.

This article covered the basics and some practical aspects. In the following article, Building Your Own PC, Part 2: Assembly Step by Step , we'll describe how to put all the components together to make a functioning PC. Users who only want to swap individual components (upgrade) will also find all the information they need.