ALU - adder/subtractor module

PCB artwork

Progress pictures

design in progress
Progress shot of the schematic and PCB design.

PCB toner transfer
The PCB toner transfer was mostly successful. The result is salvageable by passing over broken and hair-thin traces with a sharpie. Also painted over holes in the ground plane which is definitely not required, but I thought they might be confusing while drilling later (and ugly).

PCB etched
After etching, the PCB looks usable. Sharpie fixups definitely worked; might need some solder touchups here and there to fix broken traces.

first test
Running a few manual tests with DIP-switches and LEDs, after completing the assembly of the adder board.