[TUHS] Bootstrapping UNIX - how was it done

[bruner--- via TUHS]

Most of the PDP-11's I used had boot ROMs, but I do recall at least one machine where the boot procedure was

Set HALT/RUN to HALT
Press START
LOAD ADDR 777404
DEP 5
LOAD ADDR 0
Set HALT/RUN to RUN
Press START

The reset cleared all of the controller registers, so this read 64Kwords from RK05 drive 0 into memory starting at 0. A little overkill for reading one 512-byte block...

--John