Re: DAT player digital outputs

1) That device does not appear to have digital inputs or outputs. You initially stated that you were interested in capturing your digital recordings in the digital domain.
2) That device uses Firewire interface to the computer which is a dying commodity. Newer generations of computers (those that even had Firewire) are replacing it with USB3. So it isn't surprising that driver support for any Firewire devices will decrease in the future.
3) It is not at all clear that using a device like this has any significant advantage over simply running the analog output from your DAT player into whatever analog inputs are already available in your computer.