[ The PC Guide | Systems and Components Reference Guide | Floppy Disk Drives | Floppy Disk Interfacing and Configuration ]

Floppy disks are so universal that their resource usage has been all but standardized and has become quite universal as well. In fact, most peripherals won't even let you select as options the resources that are normally used by the floppy disk controller, knowing that in virtually every PC these resources are not available.

The floppy disk controller on a standard PC uses the following resources:

• Interrupt Request Line (IRQ): The standard floppy controller IRQ is 6. This is occasionally given as an option for tape accelerator cards, because they also use the floppy interface protocol and can be used as replacements for the standard floppy controller. Virtually all other peripherals will avoid IRQ 6.
• DMA Channel: The standard direct memory access (DMA) channel for the floppy controller is 2. Again, tape accelerator cards offer this is an option while most other peripherals avoid it.
• I/O Address: The standard I/O address range for the standard floppy controller is 3F0-3F7h. Strangely, this overlaps with the standard I/O address for the slave device on the primary IDE channel. In this case, however, this does not constitute a resource conflict because the overlap is something that has existed for a very long time and is compensated for. It is not an issue of concern.

In some cases these resources can be changed; in most cases they cannot. Even when they can be changed, they very rarely are since they really are the standard.

Next: Floppy Interface Cable

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