Dispatch · Lot 07

First lights and flux

Every mux and adder is down. The LEDs and headers too. The board lights up — enough to know nothing is shorted.

21 August 2026 · from the log

Soldering tiny components is delicate, error-prone, and slow. But the multiplexers and adders are finally down on the board — and so are the LEDs and pin headers.

The best part: the board lights up. That is enough validation to confirm nothing is shorted. Along the way there were bad joints and an unsoldered pin. Armed with a flashlight, I kicked back and examined the copper as closely as possible until the faults showed.

Tomato 07_alu on the bench under test — tools and board on the mat. — Fig. 1 — Board testYay · the slice on the mat

Fig. 2 — LightsSoldering loop · board cutaways

It works. I have not given myself a moment to celebrate — from raw ambition, to ordering the PCBs, to a soldered board on the desk. Recruiting season has already started, and the semester (hardest, and most fun so far) is just beginning.

Caps later

I left out the capacitors. They are not essential for the board to work immediately — tiny 0603s that matter for power-hungry switching, which is not the problem yet for basic LED testing. Brownouts can wait until full-speed runs without those caps in place.

Earlier: the first assembly pass. Next problem: something has to drive the datapath without becoming a throwaway FSM.