;--------------------------------------------------------------------
; Move_a_Block (1_Mar_84)
;------------------------
;	1) This routine moves a block of memory. The block can overlay itself.
;	2) Register Usage:
;		BC -> Byte Count
;		DE -> Destination
;		HL -> Source
;
Move_a_Block:
	ld	a,b			;If (Length of move is zero)
	or	c
	ret	z			;	Return

	push	hl
	or	a			;(clear the carry)
	sbc	hl,de			;If (Source eq Destination)
	pop	hl

	ret	z			;	Return

	jr	c,MBSk1			;Else If (Source gt Destination)
	ldir				;	Move the Block Up
	ret				;	Return

MBSk1:	push	hl
	ex	de,hl			;Else (Source lt Destination)
	or	a			;	(clear the carry)
	add	hl,bc			;	Dest:= Dest + Byte_Count
	dec	hl			;	(move pointer back to last char)
	ex	de,hl
	pop	hl

	add	hl,bc			;	Source:= Source + Byte_Count
	dec	hl			;	(move pointer back to last char)
	lddr				;	Move the Block Down
	ret				;	Return
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