> > there's no room for a wd0i, even if someone decided to make one.

> Right. The thing is that the old major and minor numbers really need to
> keep working. i.e. Even when we go to more than 8 partitions per disk (the
> hashed-out idea is 64 as it leaves lots of units yet also gives many
> partitions), wd0a will probably always be block device 0,0. 

> Thus we'll need two major devices, each with a different unit/partition
> divisioon scheme.

> That's why it can't be done in a few days (or even a few weeks :-)

If you don't mind being limited to a mere 8192 disk units, you could
do something like:  if the 0x80000 bit of the minor number is set, use the
new scheme, else use the old scheme.  This preserves old device numbers 
without chewing up new major device numbers (at the expense of really hairing
up the DISKUNIT and DISKPART macros).