Day 268/20. Honing my focus stacking skills.

I'm still messing about honing my focus stacking for macro photography. This is a part of the core memory of a late 1950's computer. Each core is about 1mm in diameter.
Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975.
Core memory uses toroids (rings) of a hard magnetic material as transformer cores, where each wire threaded through the core serves as a transformer winding.
Each core stores one bit of information. A core can be magnetized in either the clockwise or counter-clockwise direction. The value of the bit stored in a core is zero or one according to the direction of that core's magnetization.