Second fdc drive

[ohula]

I can access first fdc drive from 0x3fx ports. Which ports should I use to access second fdc drive? Or what sould I do to access second floppy drive?

[Brendan]

Hi,

I can access first fdc drive from 0x3fx ports. Which ports should I use to access second fdc drive? Or what sould I do to access second floppy drive?

If the second floppy drive is connected to the same floppy disk controller, then it uses the same I/O ports.

For a second floppy disk controller it can depend how it's configured (e.g. jumpers on an expansion card). Normally it would use I/O ports 0x0370 to 0x0377 though.


Cheers,

Brendan

[ohula]

If the second floppy drive is connected to the same floppy disk controller, then it uses the same I/O ports.

?? Than, how could I use second one? I mean how could the controller select the drive to which send command?

[Candy]

?? Than, how could I use second one? I mean how could the controller select the drive to which send command?

By using a drive select bit in the command.

[udarkman]

As I read in a tutorial each fdc controller may have 4 drives connected(Some systems does support only 2). And a system may have 2 controllers.

If I have two drives, and each connected to just one controller, I can access them using same ports, by using drive select bit. But if they are connected to seperate controllers, I have to access them by using different ports. I get fdc types from cmos. Does it show controller info or just drives? I mean how can I detect if a system have two controller and how many fdc drives connected to each controller?

I hope you understand my poor english..

[Candy]

.. a system may have 2 controllers.

Then the tutorial itself is the best reference. As far as I can tell, any normal x86 PC has only one controller, and up to 2 drives attached to it.

If I have two drives, and each connected to just one controller, I can access them using same ports, by using drive select bit. But if they are connected to seperate controllers, I have to access them by using different ports. I get fdc types from cmos. Does it show controller info or just drives?

Just the drives on the first controller.

I mean how can I detect if a system have two controller and how many fdc drives connected to each controller?

You can probe the drives, and if you know where the controllers should be you can probe them too. Try Ralf Browns Interrupt List, section PORTS (and then search for the controller).

I hope you understand my poor english..

Of course I can understand it, your english is better than most of the english I see.