X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libsrc%2Fatari%2Fxlmemchk.inc;h=d2a0795579b9cb6181303acc55af9c4d25b3c998;hb=85170998ad45cadb2064fa68349bb3a8975efd89;hp=9cc6b612c354b77dfa0c53e967be0cd6cd94dd01;hpb=d3d7499faa74db42edb71c7ee3f3fa16e7b73810;p=cc65

diff --git a/libsrc/atari/xlmemchk.inc b/libsrc/atari/xlmemchk.inc
index 9cc6b612c..d2a079557 100644
--- a/libsrc/atari/xlmemchk.inc
+++ b/libsrc/atari/xlmemchk.inc
@@ -9,7 +9,7 @@
 ; by the screen memory afterwards.
 ; 
 ; inputs:
-;	__SAVEAREA_LOAD__	-	load address of the program
+;	__STARTADDRESS__	-	load address of the program
 ; outputs:
 ;	lodadr			-	(high byte only) value to
 ;					write into RAMTOP
@@ -61,18 +61,24 @@ scrmemtst:
 	cmp	tmp
 	beq	scrmemok
 
+; if lodadr is at an exact 4K boundary, it's still ok
+
+	lda	lodadr+1
+	and	#$0f
+	beq	scrmemok
+
 ; 4K boundary will be crossed, use this 4K boundary address as lodadr
 
 al4k:	lda	lodadr+1
 	and	#$f0
-	tax
-	dex
-	stx	lodadr+1
+	sta	lodadr+1
 	bne	scrmemtst
 ; not reached
 
-
-lodadr:	.word	__SAVEAREA_LOAD__ & $FF00		; our program's load address, rounded down to page boundary
+.ifdef DEBUG
+.byte "XLMEMCHK:>"
+.endif
+lodadr:	.word	__STARTADDRESS__ & $FF00		; our program's load address, rounded down to page boundary
 tstadr:	.res	2
 lowadr:	.res	2
 tmp:	.res	1
@@ -89,6 +95,7 @@ scrmemok:
 	sbc	#>DLSZ
 	sta	lowadr+1
 
+.if 0	; this cannot happen
 ; check if a 1K boundary is crossed
 
 	lda	tstadr+1
@@ -98,6 +105,7 @@ scrmemok:
 	and	#$fc
 	cmp	tmp
 	bne	al4k		; 1K boundary will be crossed, decrease lodadr
+.endif
 
 ; address of display list is ok
 ; decrease lowadr by two