15 Sep
2016
15 Sep
'16
5:09 p.m.
On Thu, Sep 15, 2016 at 1:08 PM, David Coolbear <david at thecoolbears.org> wrote:
For 2.11BSD on the PDP-11, in the stand alone
utilities that are found on
the installation tape, the storage devices are named:
dn(x,y,z) where dn is the mnemonic for the driver, x is the controller
number, y is the unit number and z is the partition on the unit. So the
first partition on the first drive on the first MSCP controller is
ra(0,0,0). It's fairly easy form the install tape to disklabel and mkfs a
drive on a second controller.
Once UNIX is running, things change. The devices in /dev are named ra0 for
the first unit on the first controller, ra1 for the second unit on the
first controller and etc. I don't see a way in the naming convention to
identify other controllers.
My question is, what is the device name in /dev for the first drive on the
second controller?
man ra
major device number(s):
raw: 14
block: 5
minor device encoding:
bits 0007 specify partition of RA drive
bits 0070 specify RA drive
bits 0300 specify RA controller
ra{0-7}{a-h} would be the 8 partitions on the 8 drives on the first controller
ra{8-15}{a-h} would be the 8 partitions on the 8 drives on the second controller
ra{16-23}{a-h} would be the 8 partitions on the 8 drives on the third controller
ra{24-31}{a-h} would be the 8 partitions on the 8 drives on the fourth
controller.
ls -l /dev/*ra*
If you don't see the device you need than you can use /dev/MAKEDEV to
create it with the appropriate major and minor device numbers.