The size of the DCU protoboard is determined by the type of display you want to use.

If you want to use the 0.6" LED display you will need additional room for the current limiting resistors.

The DCU is programmable via the header plug assembly.

By using  the external reset test point and moving the header plug from DCU to Clock, the DCU becomes a modulo 6 counter.

Parts placement is not critical.

However the parts should be placed so there is minimal wire lengths between the I.C.s and header plug.

The Clock Logic board is 3.75" x 2.50".

The I.C.s are spaced two (2) rows apart.

I started on one end with the simple power supply, wave shaper and divide by 60 circuits.

Next is the inter-stage logic. The heart of the clock.

The various resets, divide by 6 and the 13th hour are linked to the DCUs via the 17 pin header assembly.

The Timer is used for the time set at 5 Hz via the two switches.

The 17 pin header is placed on the DCU modules side of the board.

Like the DCU, parts placement is not critical.