The image above shows the first sign of life for this PS2 keyboard interface to an Apple-1 Obtronix. It worked the first time, no problems at all. Note that as soon as I powered up the Apple-1, the interface automatically sent a Reset and a Clear Screen, and you can see that we end up at the prompt, ready for input. The keyboard LEDs lit, including Caps-lock. I then tested the Control-sequences:
RESET = Ctrl + Alt + Del
CLR SCREEN = Ctrl + C, Ctrl + L, Ctrl + R
I am back in business with a working keyboard!