// #LAYOUT# STD *       #TAKE
// #LAYOUT# *   BASIC_0 #TAKE
// #LAYOUT# *   *       #IGNORE


//
// Shift the BASIC program up to make space for a new line
//


shift_txt_up:
	
	// Last byte of source is VARTAB-1

#if !HAS_OPCODES_65CE02

	sec
	lda VARTAB+0
	sbc #$01
	sta memmove__src+0
	lda VARTAB+1
	sbc #$00
	sta memmove__src+1	

#else // HAS_OPCODES_65CE02

	lda VARTAB+0
	sta memmove__src+0
	lda VARTAB+1
	sta memmove__src+1
	dew memmove__src

#endif

	// Last byte of destination is memmove__src + .X

	clc
	txa

	adc memmove__src+0
	sta memmove__dst+0
	lda memmove__src+1
	adc #$00
	sta memmove__dst+1

	// Size is distance from OLDTXT to the end of BASIC text (VARTAB)

	lda VARTAB+0
	sec
	sbc OLDTXT+0
	sta memmove__size+0
	lda VARTAB+1
	sbc OLDTXT+1
	sta memmove__size+1

	// Perform the copy

	jmp shift_mem_up