The LSI-11 and 11/23 jumped to 173000 at startup, so (re)booting them was just hit halt on the front panel and then enter '173000G' in ODT (the built-in octal debugger). If necessary, it would only take a minute or two to type in a bootstrap somewhere in RAM and execute (my boss at the time could do that faster across the toggle keys on the front panel of his larger PDP-11 than I could type it in).
I coded several bootstraps for PDP-11/23's, managed to get 4 different devices (DX,DY 8" disks, MX 5.25" and MZ 3.5" disks) complete with CLI into 256 words (2x256 byte OTP ROMs). Careful coding time, since one had to send the listing off to someone who could burn the ROMs and post them back.
I coded several bootstraps for PDP-11/23's, managed to get 4 different devices (DX,DY 8" disks, MX 5.25" and MZ 3.5" disks) complete with CLI into 256 words (2x256 byte OTP ROMs). Careful coding time, since one had to send the listing off to someone who could burn the ROMs and post them back.