This its the first article of a new waveform generator. It took me a
while, an hour or two, to find a stuck bit on the uP data bus; turned
out it was a bad solder joint on one of those tiny quad resistor
packages. Something about their geometry makes them hard to solder and
hard to inspect.

Seems as though the most reliable thing we solder is BGAs. Who woulda
thunk it?

John