how to install a 2nd IDE drive
Many PCs come with one IDE drive, but the IDE host adapter can control at least two hard disks, and the 80-line flat, signal cable between the host adapter and the first drive generally has an open connector for the second drive.
Installing a second IDE hard disk correctly requires more mechanical skill than it does knowledge of computers or electronics. Fitting the drive into the bays and pushing and pulling on wires is the hard part. On newer PCs, all that is generally required is to set the jumper settings on the existing and new drives.
Step 1 - Install the Drive
IDE drives come with jumpers in place set to master. Move the jumper to the Slave position on the new drive. If a jumper did not come with the new drive, take the jumper off M or MA on the first drive (it will still act as Master) and place it on Slave on the second one.
Insert the new drive into a drive bay and screw it in. Do not over-tighten screws into the drive. If you want to put a 3.5" drive into a 5.25" drive bay, get an adapter that holds the drive and fits into the 5.25" bay.
Plug an available four-wire (red-black-black-yellow/orange) power cable into the drive (it only fits one way). If there are no free power cables, get a power cable splitter. Pull out an existing power connection to another drive and insert the splitter. Attach both drives to the splitter.
The connectors on the flat signal cable can be inserted up or down, so be sure to connect the second drive in the same manner as the first. One side of the cable is marked, typically with a red line or pattern of dots. Line that side up with pin 1 on the host adapter and pin 1 on the drives. If the cable isn't long enough, a longer 40-pin IDE ribbon cable can be purchased. The three connectors on the cable are common. Either one can be used for either drive or the host adapter.
Step 2 - Partition and Format the Disk
Your new drive has been low-level formatted at the factory. It must now be partitioned and high-level formatted. Most IDE drives come with a Hard Disk Manager program that lets you perform these operations, otherwise you can use the Fdisk and Format commands in DOS. See Formatting a Hard Disk under DOS Format. After these steps have been done, the new drive is ready for use.