Date   : Sun, 04 Jan 2015 22:37:56 +0000
From   : public@... (Daniel Beardsmore)
Subject: Serial console active at power-on

On 2015-01-04 20:53, J.G.Harston wrote:
> It's in MODE 0. With no keyboard plugged in the MOS "sees" every key 
> pressed *including* every keyboard link made. Which means it sees the 
> startup settings (OSBYTE 255) set to zero

Ah, so all the links are 1 when open circuit, and 0 when closed circuit .....
That's logical. Saves a few ha'pennies fitting three wire links to make MODE
7 the default ...

Even the Advanced User Guide doesn't explain this one, only that bit 3 has
to be cleared to reverse shift-break, and since the link is always clear
from the factory, this implies that the bits must be inverted.