Review week 21: math and registers

This week was about math and about programming sparingly:

• Saving registers: define and alias cost nothing, one tmp may be many things, states move into the stack with put and get.
• hcf: error 16, a spark, a small explosion – and the devices keep their last value. A lock state with acknowledgement is better.
• rand: 0 to below 1, scaled with mul, add and floor.
• sqrt, pow, exp, log: log is the natural logarithm, log10 only exists as log(x) / log(10).
• Smoothing: moving average or g = g + a · (x − g), with a start value and NaN guard.
• Project: light scenes with an edge, stepwise dimming and random flicker.

You pass from 60 %. The explanations after handing in sum up every point once more.