Breadboard planning sheet

Check the scale first

Measure the bar with a ruler. If it is not exactly 50 mm, the print scaling is wrong and the grid will not match a real board — print again at 100%.

Half board — 400 points, 30 columns

The five holes down each column, a–e or f–j, are joined inside the board; each rail is joined all the way along. How far the rails sit from row a and row j differs between makes, so line a real board up on the a–j holes.

Full board — 830 points, 63 columns

Wiring schedule

One row per jumper wire and per off-board part.

No.	Colour	From	To	What it carries

Before you build it

• Every part has an item ID, the same on the layout and the schedule.
• Every chip straddles the centre channel, one row of pins in a–e and the other in f–j, pin 1 marked.
• No part has two legs in the same five-hole column.
• One hole, one thing: every leg and every jumper end in a hole of its own.
• No jumper runs straight across a chip — it goes round the end.
• Every chip powered: its supply and 0 V pins wired to the rails.
• If the bottom rails are used, they are joined to the top ones.
• Every jumper numbered and coloured; red and black used for nothing but the supply.
• Every gate input held down to 0 V unless another gate drives it.
• Polarised parts the right way round.