1BR(4) Kernel Interfaces Manual BR(4)
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6 br - EATON BR1537/BR1711 1538[A,B,C,D] moving head disk
7
9 /sys/conf/SYSTEM:
10 NBR br_drives # EATON 1537/1711, EATON 1538A, B, C, D
11 /etc/dtab:
13 #Name Unit# Addr Vector Br Handler(s) # Comments
14 br ? 176710 254 5 brintr # Eaton 1537/8
15 major device number(s):
17 raw: 20
18 block: 11
19 minor device encoding:
20 bits 0007 specify partition of BR drive
21 bits 0070 specify BR drive
22
24 Files with minor device numbers 0 through 7 refer to various portions
25 of drive 0; minor devices 8 through 15 refer to drive 1, etc. There
26 are four drive types supported by the Eaton BR1537 and BR1711 con‐
27 trollers, these are the 1538A (50 Mb), 1538B (80 Mb), 1538C (200 Mb)
28 and 1538D (300 Mb). Capacities are unformatted megabytes. The stan‐
29 dard device names begin with ``br'' followed by the drive number and
30 then a letter a-h for partitions 0-7 respectively. The character ?
31 stands here for a drive number in the range 0-7.
32 The block files access the disk via the system's normal buffering mech‐
34 anism and may be read and written without regard to physical disk
35 records. There is also a `raw' interface which provides for direct
36 transmission between the disk and the user's read or write buffer. A
37 single read or write call results in exactly one I/O operation and
38 therefore raw I/O is considerably more efficient when many words are
39 transmitted. The names of the raw files conventionally begin with an
40 extra `r.'
41 In raw I/O the buffer must begin on a word (even) boundary, and counts
43 should be a multiple of 512 bytes (a disk sector). Likewise seek calls
44 should specify a multiple of 512 bytes.
45
47 The size (in sectors) of the pseudo-disks on each drive are as follows:
48 1538A partitions:
50 disk length cyls comments
51 br?a 18260 0 - 165 1538A has 22 sec/trk, 5 trk/cyl
52 br?b 12210 166 - 276
53 br?c 59180 277 - 814
54 br?d unused
55 br?e unused
56 br?f unused
57 br?g unused
58 br?h 89650 0 - 814
59 1538B partitions:
61 disk length cyls comments
62 br?a 18400 0 - 114 1538B has 32 sec/trk, 5 trk/cyl
63 br?b 12320 115 - 190
64 br?c 99840 191 - 814
65 br?d unused
66 br?e unused
67 br?f unused
68 br?g unused
69 br?h 99840 0 - 814
70 1538C partitions:
72 disk length cyls comments
73 br?a 18392 0 - 43 1538C has 22 sec/trk, 19 trk/cyl
74 br?b 12122 44 - 72
75 br?c 231990 73 - 627
76 br?d 78166 628 - 814
77 br?e unused
78 br?f unused
79 br?g unused
80 br?h 340670 0 - 814
81 1538D partitions:
83 disk length cyls comments
84 br?a 18240 0 - 29 1538D has 32 sec/trk, 19 trk/cyl
85 br?b 12160 30 - 49
86 br?c 232256 50 - 431
87 br?d 232256 432 - 813
88 br?e unused
89 br?f unused
90 br?g unused
91 br?h 495520 0 - 814
92
94 /dev/br[0-7][a-h] block files
95 /dev/rbr[0-7][a-h] raw files
96 /dev/MAKEDEV script to create special files
97 /dev/MAKEDEV.local script to localize special files
98
100 ra(4), ram(4), rk(4), rl(4), rx(4), si(4), xp(4), dtab(5), autocon‐
101 fig(8)
102
104 br%d%c: hard error sn%d cs2=%b ds=%b er=%b. An unrecoverable error
105 occurred during transfer of the specified sector of the specified disk
106 partition. The contents of the cs2, ds and er registers are printed in
107 octal and symbolically with bits decoded. The error was either unre‐
108 coverable, or a large number of retry attempts (including offset posi‐
109 tioning and drive recalibration) could not recover the error.
110
112 In raw I/O read and write(2) truncate file offsets to 512-byte block
113 boundaries, and write scribbles on the tail of incomplete blocks.
114 Thus, in programs that are likely to access raw devices, read, write
115 and lseek(2) should always deal in 512-byte multiples.
116 DEC-standard error logging should be supported.
118 A program to analyze the logged error information (even in its present
120 reduced form) is needed.
121 The partition tables for the file systems should be read off of each
123 pack, as they are never quite what any single installation would pre‐
124 fer, and this would make packs more portable.
125 Only the 1538D (300Mb) disk has been used with this driver, the disk‐
127 tab(5) file and newfs(8) program only know about the 1538D.
1283rd Berkeley Distribution August 20, 1988 BR(4)