Installing 4.1 BSD on SIMH

This is the procedure is loosely inspired from Naoki Hamada to install 4.0 BSD onto SIMH's VAX 11/780 emulator. I can't get the standalone programs to run on SIMH, so instead I'm using the 4.0 standalone to bootstrap 4.1. So the ini files, and initial disk prep is the same.

Requirements

• You will need a working copy of SIMH's vax780.exe for your platform.
• A modified 4.1 BSD install tape. You can download one from sourceforge
• The 4.0 standalone boot program, avilable on sourceforge
• A copy of 7zip to decompress the tape image

Preparing for installation

The first step is to decompress the tape image with 7zip. This should be very straightforward:

7zip x 4.1_BSD_19810710-modified.7z

You will need to create two ini files, one for the tape boot, and the other for the disk boot.

tboot.ini

set tto 7b
set rq dis
set lpt dis
set rl dis
set hk dis
set rq dis
set rqb dis
set rqc dis
set rqd dis
set ry dis
set ts dis
set tq dis
set dz lines=8
set rp0 rp06
at rp0 rp06.disk
set tu0 te16
at tu0 4.1_BSD_19810710-modified.tap
D 50000 20009FDE
D 50004 D0512001
D 50008 3204A101
D 5000C C113C08F
D 50010 A1D40424
D 50014 008FD00C
D 50018 C1800000
D 5001C 8F320800
D 50020 10A1FE00
D 50024 00C139D0
D 50028 04c1d004
D 5002C 07e15004
D 50030 0000f750
run 50000
run 0

dboot.ini

set tto 7b
set rq dis
set lpt dis
set rl dis
set hk dis
set rq dis
set rqb dis
set rqc dis
set rqd dis
set ry dis
set ts dis
set tq dis
set dz lines=8
set rp0 rp06
at rp0 rp06.disk
set tu0 te16
load -o boot 0
run 2

You will also need to extract the boot program. You can download it from sourceforge, or uudecode the following boot program that is injected into SIMH's memory.

Booting from tape

Simply boot up from tape by invoking SIMH's VAX 11/780 with the tape boot ini as follows:

C:\bsd40>vax780.exe tboot.ini

VAX780 simulator V3.8-1
RP: creating new file
Overwrite last track? [N] y

HALT instruction, PC: 00050033 (HALT)
=

This will get you to the bootloader which we can then use to invoke the mkfs/restore commands. There isn't any need to lowlevel format in the emulator.

=mkfs
file sys size: 7942
file system: hp(0,0)
isize = 5072
m/n = 3 500
=

Now to restore the root/boot partition:

=restor
Tape? ht(0,1)
Disk? hp(0,0)
Last chance before scribbling on disk.
End of tape
=

Hit enter when prompted "Last chance before scribbling on disk.".

Now we can invoke the boot program to load up the kernel so we can continue the install.

=boot

Boot
:

Now we can specify the disk & kernel, as follows:

: hp(0,0)vmunix
123060+27528+24628 start 0xF5C
Berkeley VAX/UNIX Version 4.9  Wed Feb 17 15:27:46 PST 1982
real mem  = 8322048
avail mem = 7738368
mcr0 at tr1
mcr1 at tr2
uba0 at tr3
dz0 at uba0 csr 160100 vec 300, ipl 15
mba0 at tr8
hp0 at mba0 drive 0
hp1 at mba0 drive 1
hp2 at mba0 drive 2
hp3 at mba0 drive 3
mba1 at tr9
ht0 at mba1 drive 0
tu0 at ht0 slave 0
tu1 at ht0 slave 1
root device?

And we will be prompted for the root device, in this case it's hp0

root device? hp0
WARNING: preposterous time in file system -- CHECK AND RESET THE DATE!
WARNING: should run interleaved swap with >= 2Mb
erase ^?, kill ^U, intr ^C
#

It is recommended that you run fsck to ensure that the 'a' partition is in good health. Run fsck as follows:

# fsck /dev/rhp0a

/dev/rhp0a
File System:

** Checking /dev/rhp0a
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Free List
663 files 4277 blocks 3346 free
#

Now we format the 'g' partition which we will then mount under /usr and restore from tape. Take note that we specify the size as that isn't detected, and that mkfs lives in /etc!

# mkfs /dev/hp0g 145673
isize = 65488
m/n = 3 500

Next we link the tape device to rmt:

cd /dev
MAKE ht0
cd /

Now we mount the partition, advance the tape, and restore.

# /etc/mount /dev/hp0g /usr
# cd /usr
# mt rew
# mt fsf 2
# tar xpb 20
#

This will take about a minute to complete.

Next we'll install a bootblock.

# dd if=/usr/mdec/uboot of=/dev/rhp0a bs=1b count=1
1+0 records in
1+0 records out
#

No create the fstab by copying the example rp file

cp /etc/fstab.rp06 /etc/fstab

And you can test that its working with a 'df'

# df
Filesystem  Mounted on  kbytes    used    free  % used
/dev/hp0a   /             7623    4278    3345     56%
/dev/hp0g   /usr        141578    9198  132380      6%

Then we fix some mount permissions, and shutdown the system.

# cd /
# chmod 755 / /usr
# sync
# sync
# sync
# sync
# ^E
Simulation stopped, PC: 80000963 (MTPR #0,#12)
sim> q
Goodbye

C:\bsd40>

The operating system is now installed.

Booting from disk

This part relies on you having extracted the 4.0 BSD boot program, as there is no console floppy in SIMH. Or I haven't figured out how to create one, so it is injected into memory and executed. Load the simulator as follows and it'll boot up to the login prompt.

C:\bsd40>vax780.exe dboot.ini

VAX780 simulator V3.8-1

Boot
: hp(0,0)vmunix
123060+27528+24628 start 0xF5C
Berkeley VAX/UNIX Version 4.9  Wed Feb 17 15:27:46 PST 1982
real mem  = 8322048
avail mem = 7738368
mcr0 at tr1
mcr1 at tr2
uba0 at tr3
dz0 at uba0 csr 160100 vec 300, ipl 15
mba0 at tr8
hp0 at mba0 drive 0
hp1 at mba0 drive 1
hp2 at mba0 drive 2
hp3 at mba0 drive 3
mba1 at tr9
ht0 at mba1 drive 0
tu0 at ht0 slave 0
tu1 at ht0 slave 1
root on hp0
WARNING: clock lost 152 days -- CHECK AND RESET THE DATE!
WARNING: should run interleaved swap with >= 2Mb
Automatic reboot in progress...
Mon Feb  2 13:31:59 GMT 1976
/dev/hp0a: 676 files 4278 blocks 3345 free
/dev/rhp0g: 1333 files 9198 blocks 132380 free
Mon Feb  2 13:31:59 GMT 1976
Mounted /usr on /dev/hp0g
preserving editor files
clearing /tmp
starting daemons: update        Mon Feb  2 13:31:59 GMT 1976

 cron accounting network mail printer.
Mon Feb  2 13:31:59 GMT 1976


Berkeley 4.1 VAX/UNIX (Amnesia-Vax)

login:

Now you can follow the `Taking the system up and down' Section of setup document.