I've been tinkering with various PDP-11 bits and such and found that
some items were hard to locate. One of those items is a
KM11. It originally was a two board set (one plugged into
another) that was used by various PDP-11s (and other devices) for
diagnostics. These sets are nearly impossible to find. I
decided to try my hand at board design and this was the first board to
attempt because it is relatively simple. I used EagleCAD
Professional as the schematic capture and board layout tool.
Here are some pictures of the first boards that I received from the
board house. I'll be stuffing them and making sure that I didn't
make any gross errors. I had the boards manufactured with gold
edge fingers, green solder mask and white silk screen. Here's a
view of the component side and the solder side of the board.
I assembled two over the weekend and here's a picture of the first one.
I tested the two boards out in my 11/40. Here's a picture of them
in the 11/40 while it was running a memory diagnostic (ZMSDD0) under
Here's a close up of the KM11s plugged into the 11/40's
backplane. Note that they are plugged into an extender.
With DEC's original design, there were two cards (one plugged into the
other). Since this board was designed to be a standard height an
extender is necessary to get the KM11 out to a point where it is useful.
Unfortunately to get a clear image I had to use a flash which washed
out the LEDs. It was quite an impressive display while the memory
diagnostic was running!