I have been working on a C# console application that will output a test application which can be sent to a PDP-11 and executed. Here is a clip of it in action on a simulated PDP-11:



This example shows the RT-11 'DEPOSIT' command in action, it allows memory locations to be set with a specific value from the command line.  I use that to enter the program and then the 'START' command to start running the code.