Hi sfxman,
Welcome to this d8b group (and thanks to the two Peter's, Peter Holmquist and 'Anyhorizon' aussie Peter for setting this new place up and so elegantly incorporating all the stuff from the old database for us d8b users).
Unfortunately, there are no easy-to-find options for a simple d8b motherboard upgrade. You don't however really need to upgrade the motherboard if you have the 300MHz version and a decent amount of ram (128 or preferably the maximum 256MB if you are running OS 5.1). This configuration runs the d8b just fine and other than a faster boot time, I don't think you'll see a massive improvement in speed, and definitely no increased functionality with a faster motherboard. The one successful and well documented upgrade story is discussed here, within the database section of this website.
http://www.sonido-7.com/d8b/maintenance.html#Post19As you are new to this group, spend some time catching up on the most exciting d8b news in years. Have a look at the following thread which documents a successful reverse-engineering and firmware hack/upgrade (by the amazing Marc Girard!) that will eventually allow us d8b users to use the d8b as a 24 channel DAW controller. Marc links to some great YouTube clips, showing the awesome potential of his new software.
viewtopic.php?f=2&t=175Not sure how you are using your d8b (ie as a digital audio router, as a full recording desk which actually does the AD/DA conversions, in conjunction with an HDR or a DAW) but this new controller paradigm seems to me like the most logical and useful extension of d8b functionality. It effectively removes the old CPU from the equation (in terms of running the software; it is still required for providing power to the console at this stage, however a new custom PSU may come about down the track). Check out Marc's great work and see if it would be helpful for your way of working.
Hope this info helps.
Cheers,
George