ZiLOG Z80 User Manual page 19

Step 4
Fit and solder connector P1.
You can fit just a single row header as used by the RC2014 standard bus. The only
reasons for the second row is to provide additional power supply pins, make the
module the same height as the others and to increase stability of the module.
To prepare the header, it should first be cut
to length (if starting with a strip more than
39 pins long) and then unwanted pins must
be removed. If you want to make the board
as easy to insert and remove as possible, you
can remove all the pins in the second row
except those shown on the schematic as
used and indicated below in green.
Take care to ensure the pins are parallel to the circuit board so that the board will be
vertical when plugged into a backplane.
18