jserv / Unix V1

Welcome to the 1st Edition UNIX repository. Here you will find the kernel source code and userland binaries which will allow you to run 1e UNIX on a PDP-11 simulator.

Build Instructions

Unless otherwise noted, file and directory names refer to this repository.

1. Download the source code for the SIMH simulator from here: http://simh.trailing-edge.com/ Or try the development repository. Make sure that you download version 3.8-0 or later.

2. Unpack SIMH somewhere. Make the BIN/ directory in SIMH at the top level. Do make pdp11 to make the pdp11 simulator in the BIN/ directory. Copy the BIN/pdp11 executable into the tools/ directory.

3. Return to the 1st Edition top-level directory. Do a make. This will do several things. It will build tools/mkfs, tools/ml and tools/apout/apout. These tools are required to build the filesystems for 1e UNIX, and the kernel. It will create kernel sources with some necessary patches, assemble the kernel and build a bootable SIMH memory image which is installed into the images directory. Finally, the make will build the rf0.dsk, rk0.dsk and tape images and install these in the images directory. You can also do a make clean to clean out the images/ and build/ directories. A make distclean will clean out the images/, build/ and tools/ directories.

Running 1st Edition UNIX

1. Run tools/pdp11 simh.cfg, and you should see this:

PDP-11 simulator V4.0-0 Beta        git commit id: a7d0b0e3
Disabling XQ
RF: buffering file in memory
TC0: 16b format, buffering file in memory
Listening on port 5555

You will receive a login: prompt:

2. Type in root followed by . You should receive a # prompt.

3. Type in an ls -l command. You should see something like this:

total    6
 43 sdrwr-  2 root    620 Jan  1 00:00:00 bin
 42 sdrwr-  2 root    250 Jan  1 00:00:00 dev
104 sdrwr-  2 root    110 Jan  1 00:00:00 etc
114 sdrwr-  2 root     50 Jan  1 00:00:00 tmp
 41 sdrwr-  7 root     70 Jan  1 00:00:00 usr

4. To change directories, use chdir, e.g. chdir /usr. The only editor installed is ed. You can find an ed tutorial in notes/edtut.txt.

5. To log in multiple times, telnet to localhost port 5555. The system is configured to allow 8 remote logins.

6. To shut the system down, press Ctrl-E to stop the simulator, and q to quit. You do not need to sync the system before shutdown.

Documentation

The manuals for 1st Edition UNIX are available here: https://www.bell-labs.com/usr/dmr/www/1stEdman.html, http://www.bitsavers.org/pdf/bellLabs/unix/UNIX_ProgrammersManual_Nov71.pdf, and http://man.cat-v.org/unix-1st/.

Some documentation of the internals of the 1st Edition UNIX are available here: http://www.bitsavers.org/pdf/bellLabs/unix/PreliminaryUnixImplementationDocument_Jun72.pdf

Details of the PDP-11/20 architecture and its peripherals can be found at: http://www.bitsavers.org/pdf/dec/pdp11/handbooks/PDP1120_Handbook_1972.pdf, and http://www.bitsavers.org/pdf/dec/pdp11/handbooks/PDP11_PeripheralsHbk_1972.pdf.

The C compiler from 2nd Edition UNIX is also installed and works, but the language is a very early dialect of C. The closest reference to the language at this point in time is this, but it is probably 2 years too late: https://www.bell-labs.com/usr/dmr/www/cman74.pdf

The userland binaries come from a period somewhere between the 1st and 2nd Edition of UNIX. You may find the 2e manuals useful too: http://www.bitsavers.org/pdf/bellLabs/unix/Unix_2nd_Edition_Manual_Jun72.pdf.

Repository Layout

• pages/
  • OCR'd pages from the PreliminaryUnixImplementation document
• rebuilt/
  • kernel source rebuilt from the OCR'd pages, as asm files
• patches/
  • patches to rebuilt/ files to get kernel to run
• fs/
  • userland binaries and files, used to make rf0.dsk and rk0.dsk
• src/
  • source code for userland: there is not much available
• tools/
  • tools and scripts to build the kernel and filesystem
• build/
  • build area: patched kernel files, patched filesystems
• images/
  • final disk and tape images to be used by the SIMH simulator
• notes/
  • notes on the work done to get 1e UNIX to run again