UNIX V1 bootstrap The UNIX V1 bootstrap procedure is described in UNIX_ProgammersManual_Nov71.pdf, section BOOT PROCEDURES (VII). To install the bootstrap and kernel, prior to running the V1 system, use the boot/installboot command. This will install the bos program as well as the recently-built kernel from build/loadfile into the warm boot area of the rf0 disk: boot/installboot The system can be warm booted with: tools/pdp11 boot/simh.cfg NOTE: For using kernels built using the V2 assembler, all of the following should refer to msys2, instead of msys. Alternatively, everything can be installed while running under the V1 system using the following procedure: First, build the support programs: bos and msys chdir /usr/boot sh run Install the bootstrap and unix: msys b bos msys u wunix If you build a kernel under V1, then you can install it into the warm boot area with: msys u name_of_kernel You can install it into the cold boot area (such as for testing) with: msys 1 name_of_kernel The default installation does not copy an image into the cold boot area. However, if the cold boot area is being used for testing new kernels, then the kernel can be bootstrapped using: tools/pdp11 boot/simh_cold.cfg NOTE: the 32W bootstrap normally resides at location 173700, but because the simulator does not have memory at that location, the current bootstrap is copied into 073700 in the simulator. This does not change the behavior at all.