On Mon, 2 Dec 1996, The Great Mr. Kurtz [David A. Gatwood] wrote:

> Don't know if anybody answered this, but the mapping changed a while back.
> The sd partition letters now only refer to the ones that are A/UX
> partitions.  MacOS partitions are skipped.  This eliminates the need for
> the A/UX stuff to be in the first 8 partitions like it used to require.
> Of course, if anybody gets in-kernel HFS working, that will have to change
> back....  There ought to be a better answer, like creating a new type, say
> hd for HFS Disk, with the same mapping scheme as the sd's use, except only
> map the HFS partitions, instead of only mapping in the A/UX partitions.
> Thoughts?

I don;t think that that is quite right.  The mapping was changed so that 
we'd find the A/UX partitions first (at least, the A/UX Root or Root & 
Usr partitions).  The MacOS partitions are still there, if there's any 
room left in the faked-out, in-core disklabel, as shown by the HFS entries
in the following output of disklabel on one of my drives:

# /dev/rsd1c:
type: SCSI
disk: SCSI disk
label: fictitious
flags:
bytes/sector: 512
sectors/track: 91
tracks/cylinder: 25
sectors/cylinder: 2275
cylinders: 3055
total sectors: 6976375
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0 

8 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  a:    45500     2275    4.2BSD        0     0     0 	# (Cyl.    1 - 20)
  b:   227500    47775      swap                    	# (Cyl.   21 - 120)
  c:  6976375        0    unused        0     0       	# (Cyl.    0 - 3066*)
  d:      192     2083   unknown                    	# (Cyl.    0*- 0*)
  e:  2630689   275275   unknown                    	# (Cyl.  121 - 1277*)
  f:  2097151  2905964       HFS                    	# (Cyl. 1277*- 2199*)
  g:   400400  5003115    4.2BSD        0     0     0 	# (Cyl. 2199*- 2375)
  h:  1048574  5403515       HFS                    	# (Cyl. 2375*- 2836*)