“MP/M II can execute one command upon cold boot. However, the system can execute any number of commands upon cold boot if the initial command is SUBMIT.” – Application Note 10, 9/14/81, in the MP/M Programmer’s Guide.
It works great. So of course I tried creating $n$.SUP files for the other consoles and it *almost works* -- alas, with 0 and 3's .SUP file in place...
It works great. So of course I tried creating $n$.SUP files for the other consoles and it *almost works* -- alas, with 0 and 3's .SUP file in place...