In order to make them work, the path to TURBODEV.SYS (in the TURBO.SYS config file) must be valid. Also, if you want to boot the turbo-card from floppy, you must specify so by using the /f parameter, and the disk in drive A: must be bootable.

The /! switch activates the coprocessor, but it should be noted that the driver warns you about doing so.