; TRS80_2-Page151.asm
;	
; ***************** SCROLL SCREEN SUBROUTINE ******************		
; SCROLLS LINES 1-11 UP TO LINES 0-10. FILL LINE 11 WITH BLANKS.
; ENTRY: NO PARAMETERS.
;        ALL REGISTERS SAVED.
; *************************************************************	
.ORG	0000h

CCRSR:	.EQU	3C00h		; ADDED FOR TESTING PURPOSES.
SCREEN:	.EQU	3C00h		; ADDED FOR TESTING PURPOSES.
LINE0:	.EQU	3C00h + 00h	; ADDED FOR TESTING PURPOSES.
LINE1:	.EQU	3C00h + 40h	; ADDED FOR TESTING PURPOSES.
LINE11:	.EQU	3C00h + 300h ; ADDED FOR TESTING PURPOSES.
		LD	SP,	0080h		; ADDED FOR TESTING PURPOSES.
		CALL SCROLL			; ADDED FOR TESTING PURPOSES.	
		
SCROLL:	PUSH 	AF		; SAVE REGISTERS.
		PUSH	BC
		PUSH 	DE
		PUSH 	HL
		LD	DE,	SCREEN		; START OF SCREEN.
		LD	HL,	LINE1		; LINE 1.
		LD	BC,	1024 - 256	; # TO MOVE.
		LDIR				; BLOCK MOVE TO DO THE ACTUAL SCROLLING.
		LD 	DE,	LINE11		; START OF LINE 11.
		LD	A,	' '			; SPACE CHARACTER.
		LD	BC,	64			; # TO FILL. 64 CHARACTERS PER LINE.
		CALL	FILLCH		; FILLS 12 LINES WITH BLANKS AFTER SCROLL.;;;;;;;;;;;;;
		LD	HL,	LINE11		; START OF LINE11.
		LD	(CCRSR), HL		; RESET.
		POP	HL				; RESTORE REGISTERS.
		POP	DE
		POP BC
		POP AF
		RET					; RETURN

.END