1. Hard Drive. You may have a low capacity drive (under 1 GB), and want to add an additional drive. That is easy if you don't already have your hard drive ribbon cable full.
   1. IDE drives can only have two drives per ribbon cable, and there is normally only two 40-pin interfaces to your motherboard. You can purchase an additional interface card if necessary.

   2. You may want to purchase a SCSI controller card if you have few expansion slots. A SCSI controller will allow you to connect up to 7 devices to the SCSI cable and controller.

   3. If you already have a drive and want to keep it, you will have to make one of the drives the "master" disk, and the other a "slave" disk. Read your manual. Usually, the same brand of drive will be easiest to configure.

2. Master Drive. The "master" drive will be your "bootable" hard drive. It is the one onto which you will have loaded your operating system. You will have to set the proper "jumper" or "switch" to indicate it is the master drive. Normally, you would use your largest drive as the master drive.

3. Slave Drive. The "slave" drive will normally be your smallest drive; and it will be used as a storage area.

4. Generally, if you have two disks, they are easier to work with if they are of the same manufacturer or brand.

5. The drives must be the same type, i.e. IDE or SCSI, if they are to be on the same cable.

REMEMBER THIS: When adding a new hard drive, you will have to define it in your "setup" (CMOS), then you will need to partition it, then format it.