>>>>> "J" == J D Forinash <foxtrot@cc.gatech.edu> writes:

  J> Another thing to think about is that VMUs are easily shufflable around--
  J> if you've got a particular VMU in your fstab (or the bsd equivalent; 
  J> I'm not much of a BSD geek yet), you're going to want to mount it in
  J> the same place and you're probably not going to want to remember which 
  J> port of which controller you had it in. It might be a neat idea to 
[...]

This should probably be handled the same was as e.g. USB/Firewire
storage devices (whatever way that is, I'm no BSD guru either...  :)


  >> So, maybe (partition*24)+(port*6)+slot?  Or is it better to have
  >> bitfields, like (partition*32)+(port*8)+slot?  Some other order?  (I
  >> think partition should go at the top anyway, since you'll only be
  >> using partition 0 in practice.)

  J> Makes sense, but I suspect at the top you meant port*4. (4 ports, 6 slots.)

No.  6 slots, therefore port*6.  If it were port*4, both port 0 slot 4
and port 1 slot 0 would get minor number 4.  You would out the math.  ;)


  J> I'd go with the bitfield version-- you'll need 3 for the slot, 2 for the 
  J> port, and 5 for the partition, which puts you still well shy of the million

8 bits for partition.  256 partitions, remember?


  J> mark. Having a few extra might be useful for future development (perhaps
  J> Dreamcast 2 will have 8 controller ports?), so perhaps something more like
  J> 4 for the slot, 4 for the port, and the rest for partitions would be a 

Rather than trying to support more ports, having some bits for maple
bus number would be a better idea.  The way the protocol works, there
can't be more than 4 ports, but there could theoretically be multiple
maple buses (so an 8 port Dreamcast could be made by having two buses
of four ports each).


  J> better bet. Hm, or would having extras now get confusing? Is there a 
  J> hardware spec for how many controller ports the console could support? 
  J> (After all, it seems you can have 6 slots on a port even though you can 
  J> only fit two memory modules in a normal controller...)

The controller also counts as a slot.


  J> <lurk>, and perhaps it's not even worth real salt, make it shakers of 
  J> potassium chloride.

I prefer ammonium chloride.  *yum*


  // Marcus