Sonic: I need it to drive my Hardware (develover-board) on
the floppy-connector. Only two things are there,to damage
the signals.
1.The signal "Drive Select A" working not correkt.
It's going from high to low, but not back. "Drive Select B"
works correkt.

2. If i call a testprogramm to drive a signal over "drive select B",
it works correkt, but if i call it once mal , it shows me a Error.
It can't open now the trackdisk.device.

Please clarify, i don't understand everything.
At which moment should it bring high Drive select A where it doesn't? May be a snippet from your source code would help.
In fact if you don't have the actial drive, you won't be able to open the appropriate unit. It's strange that you can open it for the first time.

P.S. I guess your hardware is not a floppy and doesn't emulate it. In this case i would suggest you to write your own driver for your own board. It will operate in a manner you need.

After some investigation...
1. One of sel signals is always active, it is last selected drive. There's no way in i82077 controiller to deselect all drives.
2. You can use motor signals instead of them. However:
a) Currently the driver forgets to turn motor signal off if the drive is absent.
b) Note that these signals are activated at least once when the driver is loaded into the memory. It is necessary to check if the drive is present and determine initial disk state (absent or present). Othewrise it's impossible with i82077.
3. I can fix the device so that it will always open even if there's no drive on the selected unit (and fix (2a)). However be careful with custom hardware - see (2b), there's no workaround.
So the best way is to write your own device driver.