CableWholesale ATA-100/133 18-Inch FC 40 Pin 40TP Round Cable, Black (21AT-10118RBK) IDE slots on the motherboard can only support up to 2 devices. Devices that use IDE cables can include CD-ROMs, Zip drives, hard drives, DVD-ROMs, CD burners, etc. IDE cables are designed to connect internal devices in your computer to the motherboard. Round IDE cables are much more flexible than regular IDE cables and provide better air flow throughout the computer.