The backplane was designed in accordance with the mechanical specification
for VME backplanes. The clock generation board is a double height extended
eurocard. It contains an oscillator module, a 74AC74 to divide the speed of
the oscillator by two, 10 74ACT04s to drive the frame and clock
signals across the backplane and a 74LS14 to drive the reset lines.
It has been found necessary to add series termination to the outputs
of all the clock line drivers. 
resistors seem sufficient.