Q. What are the rules for connecting IDE drive cables (hard disk, CD-ROM, ATA/66/100/133, etc.)?
A. If it is a 40-conductor IDE (http://duxcw.com/digest/guides/hd/hd3.htm) cable, it makes no difference which connector is connected to what. Any of them can be connected to the motherboard or drives. If it is an 80-conductor (it has 40 pins like the 40-conductor cable) ATA/66/100/133 cable it makes a difference what is connected to what. The blue connector is connected to the system board. The black connector at one end of the cable is goes to the MASTER drive. The gray one in the middle is used for slave devices. Although an Ultra ATA/66 device should work fine in either the black or the gray connector, if you are having difficulty, connect the drive to the black connector. ATA/66/100/133 cables (all are the came ATA/66 cable) vary. Some are labeled "SYSTEM," "MASTER," and "SLAVE." Most IDE cables have red-strip to identify pin-1; others have a blue strip. It goes to pin-1 on the motherboard and on the drives. Pin 1 on all IDE drives I have seen is towards the power connector (floppy drives vary).