Re: [TUHS] /dev/drum - TUHS

24 Apr 2018

...
 Date: Mon, 23 Apr 2018 13:51:07 -0400
From: Clem Cole &lt;clemc(a)ccc.com&gt;
To: Ron Natalie &lt;ron(a)ronnatalie.com&gt;
Cc: Tim Bradshaw &lt;tfb(a)tfeb.org&gt;, TUHS main list &lt;tuhs(a)minnie.tuhs.org&gt;
Subject: Re: [TUHS] /dev/drum
Message-ID:
        &lt;CAC20D2PEzAayjfaQN+-&gt;kQS=H7npcEZ_OKXL1ffPxak5b2ENv4Q(a)mail.gmail.com&gt;
Content-Type: text/plain; charset="utf-8" 
... some stuff removed ...

...
 Exactly...   For instance an RK04 was less that 5K
blocks (4620 or some
such - I've forgotten the actually amount).  The disk was mkfs'ed to the
first 4K and the left over was give to the swap system.   By the time of
4.X, the RP06 was 'partitioned' into 'rings' (some overlapping).  The
'a'.
partition was root, the 'b' was swap and one fo the others was the rest.
Later the 'c' was a short form for copying the entire disk. 
Wondered why, but I guess now I know that's the reason Digital UNIX on
alpha used the same disk layout. From a AlphaServer DS10 running
DU4.0g, output "disklabel -r rz16a"

# /dev/rrz16a:
type: SCSI
disk: BB009222
label:
flags:
bytes/sector: 512
sectors/track: 168
tracks/cylinder: 20
sectors/cylinder: 3360
cylinders: 5273
sectors/unit: 17773524
rpm: 7200
interleave: 1
trackskew: 66
cylinderskew: 83
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0

8 partitions:
#          size     offset    fstype   [fsize bsize   cpg]      #
NOTE: values not exact
  a:     524288          0     AdvFS                    	# (Cyl.    0 - 156*)
  b:    1572864     524288      swap                    	# (Cyl.  156*- 624*)
  c:   17773524          0    unused        0     0       	# (Cyl.    0 - 5289*)
  d:          0          0    unused        0     0       	# (Cyl.    0 - -1)
  e:          0          0    unused        0     0       	# (Cyl.    0 - -1)
  f:          0          0    unused        0     0       	# (Cyl.    0 - -1)
  g:    4194304    2097152     AdvFS                    	# (Cyl.  624*- 1872*)
  h:   11482068    6291456     AdvFS                    	# (Cyl. 1872*- 5289*)