AGA dual playfield enhancement

[james666]

Another amos.library hack that adds support for lowres 8 bit Dual Playfield mode (2x16 colour screens) if AGA is available.  This is the easiest AGA enhancement because it doesn't need any changes to the existing data structures or AMOS syntax.  You just open two normal 16 colour screens and apply Dual Playfield as usual.  The library returns the normal "Can't set dual playfield" error if AGA isn't available.  The Palette command works as before with 12-bit precision.  In 8-bit Dual Playfield mode, colour registers 0-15 are applied to the first playfield and registers 16-31 to the second.  The source code and a simple AMOS demo are included in the attachment.

[BooBoo]

Looking forward to trying this