Breadboard
Breadboard is chosen as the base of these assemblies to eliminate the need of soldering.
The internal structure of the breadboard shown below reveals that 5 holes in the middle of the board are all connected and holes along each vertical lines on the sides of the board are also connected:

Integrated Circuit (IC) chips in DIP package should be laid across the middle groove:
Good example of wiring on top of breadboards:
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Bad example:
