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fs.5: format under UNIX-7 roff!

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mention boot & swap track locations
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phil
2019-10-30 01:34:25 -04:00
parent db6bcaef6e
commit c5c29ec771
1 changed files with 109 additions and 90 deletions
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man/fs.5
+41 -22
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@@ -4,14 +4,18 @@ NAME format of file system
.sp
SYNOPSIS --
.sp
DESCRIPTION The RB09 fixed head disk has 8,000 64-word
blocks on each of its two surfaces. Unix uses
DESCRIPTION
.in 8
The RB09 fixed head disk has 8,000 64-word
blocks (100 tracks of 80 bloocks)
on each of its two surfaces. The Unix filesystem
is stored in the first 80 tracks of
the second surface (physical blocks 8,000 to
15,999) and numbers them from logical block 0 to
logical block 7,999. The following discussion
refers to logical blocks.
14,399 -- physical tracks 100 to 179)
and numbers them from logical block 0 to
logical block 6,399.
.sp
The Unix filesystem is divided into 8,000 blocks
The Unix filesystem is divided into 6,400 logical blocks
of 64 words per block. Block 0 is the "sysdata"
block. The first word points to the first block
of the free-storage map. Each block in the
@@ -26,44 +30,56 @@ DESCRIPTION The RB09 fixed head disk has 8,000 64-word
.sp
I-numbers begin at 1, and the storage for
i-nodes begins at block 2. Blocks 2 to 711
contain the i-nodes, with five consecutive
contain the i-nodes, with five 12-word
i-nodes per block. Certain i-nodes are reserved
for special files, directories and devices:
.sp
1 The core file written by "sys save" or a
bad system call
.nf
1 The core file written by "sys save"
or a bad system call
2 The "dd" directory directory
3 The "system" directory
6 The "ttyin" special file
7 The "keyboard" (graphic-2) special file
8 The "pptin" (paper tape reader) special
file
7 The "keyboard" (GRAPHIC-2)
special file
8 The "pptin" (paper tape reader)
special file
10 The "ttyout" special file
11 The "display" (graphic-2) special file
12 The "pptout" (paper tape punch) special
file
11 The "display" (GRAPHIC-2)
special file
12 The "pptout" (paper tape punch)
special file
.fi
.sp
There is only one file system which is always
mounted; it resides on the RB disk. This device
is also used for swapping. The swap areas are at
the high blocks on this device: blocks 6,400 to
7,999. These blocks do not appear in the free
list.
mounted; it resides on the RB disk.
.sp
The last twenty tracks of the second disk surface
are use for bootable images and swapping:
.sp
Each physical track from 180 to 189
contains a bootable system image of 3K words.
.sp
Each physical track from 190 to 199 is used to swap
a user process (4K words plus a 64-word swapable
"userdata" area).
.sp
Each i-node represents one file. The format of
an i-node is as follows, where the left column
represents the offset in words from the
beginning of the i-node:
.sp
.nf
0 flags (see below)
1 first indirect block or contents block
1 first indirect block or data block
...
7 seventh indirect block or contents block
7 seventh indirect block or data block
8 user ID of owner
9 link count
10 size in words
11 unique value assigned at creation
.sp
.in 8
The flags are as follows:
.sp
400000 i-node is allocated
@@ -75,6 +91,8 @@ DESCRIPTION The RB09 fixed head disk has 8,000 64-word
000004 write, owner
000002 read, non-owner
000001 write, non-owner
.fi
.in 8
.sp
The allocated bit (flag ??????) is believed even
if the i-node map says the i-node is free; thus
@@ -107,6 +125,7 @@ DESCRIPTION The RB09 fixed head disk has 8,000 64-word
corresponding block has never been allocated.
Such a missing block reads as if it contained
all zero words.
.in 0
.sp
FILES --
.sp