UNIX Fourth Edition

Here you can find the contents of the UNIX v4 tape ready for bootstrapping, including a tar file of the filesystem.

• unix_v4.tap is the original tape file in simh format
• bootstrap are the first 38400 bytes of the tape
• disk.rk is the rest of the tape, an RK05 image
• unix_v4.tar is the filesystem extracted
• install.ini is an ini file for simh to install the system
• boot.ini is an ini file for simh to boot the system

At first I extracted the disk image manually from the tape, which resulted in bootstrap and disk.rk. These are really nothing more than the first 38400 bytes of the raw tape content and the rest. Because unix_v4.tap is block based, one first has to strip it of its block sizes to get the raw content.

Actually it's easier to just use the tape as it is and install a new system from it.

Installing the system

To install the system we just dump an RK05 disk image from tape to disk:

% pdp11 boot.ini

[...]
        ; boot from TM0, now in mboot
=list
dldr
dtf
list
mboot
mcopy
rkf
tboot
uboot
=mcopy
'p' for rp; 'k' for rk
k
disk offset
0
tape offset
75
count
4205
=

Afterwards, we can just load uboot from tape to start UNIX:

=uboot
k
unix

login: root
# ls
bin
dev
etc
lib
mnt
tmp
unix
usr
# sync
# sync
# sync
# ^E        ; end emulation

Running the system

To boot the system we don't need the tape. Instead, we load uboot directly from the boot sector. We specify k for RK05, then the filename unix.

% pdp11 boot.ini

[...]
        ; boot from RK0, now in uboot
k
unix

login: root
#