I am sorry to say I am giving up on my DM.  I have loved this board since I took it out of the box.  Used mainly as an interface/control surface for pro tools.  I have upgraded my Mac to an M2 silicone.  I've been holding out hoping someone might be able to write a driver to get the firewire to work on the new computer but I'm done waiting.  Also I am done with Tascam.  Was not happy when they stopped making these boards but  to have to let it go because they can't/won't provide a software driver  update is beyond frustrating.  They want me to buy a new product of theirs?  Why would I?  Nothing they offer compares to the DM and besides just, NO lol.  I have ordered on Presonus StudioLive 32s.
That being said if you have any interest in a nice DM4800 with some tasty extras, you will find it listed on Reverb.com
				
			That being said if you have any interest in a nice DM4800 with some tasty extras, you will find it listed on Reverb.com