Function Name: SWAPPER

Purpose: Switch between 40 and 80 columns
Call address: $FF5F (hex) 65375 (decimal)
Preparation:

	Registers:	none
	Memory:		system map
	Flags:		none
	Calls:		none

	Registers:	.A used
			.X used
			.Y used
	Memory:		local variables swapped
	Flags:		none

Description: SWAPPER is an Editor utility used to switch between the 40-column VIC (composite) video display and the 80-column 8563 (RGBI) video display. The routine simply swaps local (associated with a particular screen) variables, TAB tables and line wrap maps with those describing the other screen. The MSB of MODE, location $D7, is toggled by SWAPPER to indicate the current display mode: $80= 80-column, $00= 40-column.

EXAMPLE:

	LDA	$D7	;check display mode
	BMI	is_80	;branch if 80-column
	JSR	$FF5F	;switch from 40 to 80