Clip Window Control Register

Number	$1C
Readable	Yes
Writable	Yes
Short Description	Controls (resets) the clip-window registers indices.

Write:

Bit	Function
7-4	Reserved, must be 0
3	reset the Tilemap clip-window register index (by writing 1).
2	reset the ULA/LoRes clip-window register index (by writing 1).
1	reset the Sprite clip-window register index (by writing 1).
0	reset the Layer 2 clip-window register index (by writing 1).

Read:

Bit	Function
7-6	the current Tilemap clip-window register index
5-4	the current Layer 2 clip-window register index
3-2	the current Sprite clip-window register index
1-0	the current ULA/LoRes clip-window register index

Each read index maps as 0: X1, 1: X2, 2: Y1 and 3: Y2 (the same order how the coordinates are written to particular clip-window register).