Update (2/7/2021): Rather than using a 220uf electrolytic, use a 47 uf tantalum capacitor instead.
Update (2/5/2021): A previous version of this page said to add the capacitor to U1… that was incorrect! It is definitely on U4, the MC6875!
All existing versions, including up to 3A, of the SS-50 6800 CPU Board have a problem where power-on reset does not work. A part is missing. This is not a severe problem, as the user can press the RESET button on the board or the motherboard to do the reset, but it can be easily fixed.
You’ll need to solder a 47 uf, 16v (or higher) tantalum capacitor to the back of the board. The negative side of the capacitor goes to U4 pin 8 (ground) and the positive side goes to U4 pin 12. This is a picture from when I was using a much larger electrolytic capacitor, but I’ve switched to a 47 uf tantalum cap for all new boards:
All future revisions of the board will include this fix.