2nd W 2006
Attempt at writing a test that shows when t gets copied to v on the second write to 0x2006.
Through questionable code and blargg's nmi sync code, it's possible to time a write with a 1 dot variance.
Press right or left to increase or decrease the dot offset by one, respectively.
For example, in nintedulator: the second "sta 0x2006" starts at dots 236-237 at offset 0, and dots 244-245 at offset 8 (max).
The test draws a row of triangles. If they appear as a pixel perfect staircase, the t->v transfer happened after the Y increment at dot 256. If not, it happened before.
Todo: add explanation of output (on screen), better output