> it turns out there's an error in the KY11-LB drawings.
> ...
> I have 'fixed' a copy of that page from the print set, and will (soon)
> issue an updated PDF.
OK, I finally got a round tuit; new version here:
http://ana-3.lcs.mit.edu/~jnc/tech/pdp11/MP00015_KY11-LB_Jan78.pdf
(
So, now that I have the 85S68 datasheet in hand, it turns out there's an error
in the KY11-LB drawings. (I just couldn't understand how the circuit could
possibly work, until I discovered that!)
On the two RAM chips (E11 and E27, used to hold the bus address, keypad data,
etc) the "Output Store" a
