I took the hist of a basic MACD (12, 26, 9), made it a line, multiplied it by 3, then shifted it up or down based on the difference between the EMA50 and the EMA200. So it's basically a balance between short term MA convergence/divergence and long term EMA difference. You can change the divider of the EMA difference so it becomes more or less weighted. I have it set at 5 by default, but 1 would make it heavily EMA50/200 long-term weighted, whereas 10 would make it almost all MACD short-term weighted.