====== Installation of 2.11BSD on SIMH ======
I assume you have [[http://simh.trailing-edge.com/ | SIMH]] binary "pdp11" available. You can download a binary version for Linux {{pdp11:211bsd:pdp11.gz | from here}}.

For impatient: you can get the resulting root disk image from here:
{{pdp11:211bsd:211bsd.dsk.gz | "211bsd.dsk.gz"}} (gzipped 29 Mbytes, unpacked 170 Mbytes). To boot, ungzip the disk image and use the following SIMH commands:
  sim> set cpu 11/44 1M
  sim> attach rp0 211bsd.dsk
  sim> boot rp0

On boot prompt ':', just hit Enter. On single user prompt, type ^D. Login as root, password is empty.

===== Download files =====
To install 2.11BSD you need a file {{pdp11:211bsd:211bsd.tap.gz | "211bsd.tap.gz"}} (gzipped 28 Mbytes), which contains an image of distribution tape. Ungzip it before installation.

The original 2.11BSD distribution files could be found at
[[https://www.tuhs.org/Archive/Distributions/UCB/2.11BSD/ | The Unix History]] archive, but you will not need them.

The tape contains following files:

^  File  ^  Size  ^     Contents  ^
|  0  |  512*1    | primary tape boot block  |
|     |  512*1    | boot block (some tape boot ROMs go for this copy)  |
|     |  512*69   | standalone boot program  |
|  1  |  1024*37  | standalone disklabel  |
|  2  |  1024*33  | standalone mkfs(8)  |
|  3  |  1024*35  | standalone restor(8)  |
|  4  |  1024*32  | standalone icheck(8)  |
|  5  |  10240*285   | dump of ..root.. file system  |
|  6  |  10240*3368  | tar dump of /usr, excepting /usr/src  |
|  7  |  10240*519   | tar dump of /usr/src/include and /usr/src/sys  |
|  8  |  10240*4092  | tar dump of /usr/src, excepting include and sys  |

===== Create disk image =====
Create an RP06 disk image file "root.dsk". Device RP06 has
C/H/S geometry 815/19/22, total 815*19*22/2 = 170335 kbytes.

	$ dd bs=1k count=170335 < /dev/zero > root.dsk

Another choice is RP05 with geometry 411/19/22, total 85899 kbytes.

===== Create script for simulator =====
Create file "install.simh":

	set cpu 11/44 1M
	show cpu
	attach tm0 211bsd.tap
	attach rp0 root.dsk
	boot tm0

===== Run simulator =====
Run SIMH:

	$ pdp11 install.simh

You will see:
<code>
PDP-11 simulator V3.6-1
Disabling XQ
CPU, 11/44, FPP, NOCIS, autoconfiguration on, 1024KB

44Boot from tm(0,0,0) at 0172522
:
</code>

===== Disklabel =====
To start disklabel, enter "tm(0,1)" :

	: tm(0,1)
	Boot: bootdev=0401 bootcsr=0172522
	disklabel
	Disk?

Enter "xp(0,0)".

Modify disklabel, create:
	- partition 'c' on a whole disk - size 340670, offset 0, type unused
	- partition 'b' for swap - size 8360, offset 332310, type swap
	- partition 'a' for root - size 332310, offset 0, type 2.11BSD

The manual on using standalone disklabel is available at page 50 of {{pdp11:211bsd:211bsd-setup.pdf | 2.11BSD installation guide}}.

You must see:
	3 partitions:
	#        size   offset    fstype   [fsize bsize]
	a:     332310        0    2.11BSD    1024 1024     # (Cyl. 0 - 794)
	b:       8360   332310    swap                     # (Cyl. 795 - 814)
	c:     340670        0    unused     1024 1024     # (Cyl. 0 - 814)

Do not forget to write a new label to disk before quit.
After quit you will see boot prompt again:

	44Boot from tm(0,0,1) at 0172522
	:

===== Create root filesystem =====
To create root filesystem, enter "tm(0,2)":

	Boot: bootdev=0402 bootcsr=0172522
	Mkfs
	file system:

Enter "xp(0,0)". Then enter default values:
<code>
file sys size [166155]:
bytes per inode [4096]:
interleaving factor (m; 2 default):
interleaving modulus (n; 209 default):
isize = 41536
m/n = 2 209
Exit called

44Boot from tm(0,0,2) at 0172522
:
</code>

===== Restore root filesystem =====
To restore the root file system, type "tm(0,3)":

	Boot: bootdev=0403 bootcsr=0172522
	Restor
	Tape?

For tape, enter "tm(0,5)". For disk, enter "xp(0,0)":

	Tape? tm(0,5)
	Disk? xp(0,0)
	Last chance before scribbling on disk.

Type a carriage return to start. When restore finished, you will see:
<code>
End of tape

44Boot from tm(0,0,3) at 0172522
:
</code>

===== Boot from disk =====
To boot from disk, type "xp(0,0)unix":
<code>
Boot: bootdev=05000 bootcsr=0176700

2.11 BSD UNIX #115: Sat Apr 22 19:07:25 PDT 2000
    sms1@curly.2bsd.com:/usr/src/sys/GENERIC


phys mem  = 1048576
avail mem = 824640
user mem  = 307200

June  8 21:21:24 init: configure system

hk 0 csr 177440 vector 210 attached
ht ? csr 172440 vector 224 skipped:  No CSR.
ra 0 csr 172150 vector 154 vectorset attached
rl 0 csr 174400 vector 160 attached
tm 0 csr 172520 vector 224 attached
tms 0 csr 174500 vector 260 vectorset attached
ts ? csr 172520 vector 224 interrupt vector already in use.
xp 0 csr 176700 vector 254 attached
erase, kill ^U, intr ^C
#
</code>

You are in single-user Unix now!

To make disk bootable, you need to install an RP06 boot record:

	# dd if=/mdec/hpuboot of=/dev/rxp0a count=1

Set date:

	# date yymmddhhmm

===== Read /usr =====
Now we need to read /usr from tape.

	# cd /dev
	# rm *mt*
	# ./MAKEDEV tm0
	# sync
	# cd /usr
	# mt rew
	# mt fsf 6
	# tar xpbf 20 /dev/rmt12
	# sync

Done /usr.

===== Read /usr/src =====
Now read sources from tape to /usr/src:

	# mkdir /usr/src
	# cd /usr/src
	# mt -f /dev/rmt12 fsf
	# tar xpbf 20 /dev/rmt12
	# sync
	# mt -f /dev/rmt12 fsf
	# tar xpbf 20 /dev/rmt12
	# cd /
	# chmod 755 / /usr /usr/src /usr/src/sys
	# sync

===== Fix fstab and swap =====
Edit /etc/fstab and replace /dev/ra0 by /dev/xp0. Use vi editor.

Set swapping on /dev/xp0b:
  # cd /dev
  # rm swap drum
  # mknod swap b 10 1
  # mknod drum b 10 1
  # sync

All done. After installation, you will have 80 magabytes free space:

	# df
	Filesystem  1K-blocks     Used    Avail Capacity  Mounted on
	/dev/xp0a      163557    82734    80823    51%    /

===== How to stop =====
To stop the system cleanly, run:
  halt
and wait until SIMH prompt appears:
<code>
syncing disks... done
halting

HALT instruction, PC: 000014 (MOV #1,17406)
sim>
</code>

Then enter "q".