X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=3sys;a=blobdiff_plain;f=sys1%2Fkern%2Fsrc%2Fvga.c;fp=sys1%2Fkern%2Fsrc%2Fvga.c;h=c1edd9a7d92969399d8357be0fab6030f2865b3d;hp=ae7c04991981d0d8040d1a71e9c1145b15785739;hb=6ccd3a47d05be145256a79a1de100f01ebd16a79;hpb=ebc5d64326bba69c74ae103fad61b04a542f9eb2

diff --git a/sys1/kern/src/vga.c b/sys1/kern/src/vga.c
index ae7c049..c1edd9a 100644
--- a/sys1/kern/src/vga.c
+++ b/sys1/kern/src/vga.c
@@ -30,7 +30,7 @@ void vga_setcursor(int x, int y)
 
 void vga_scroll(int s)
 {
-	yoffs = s % 25;
+	yoffs = s & 0x1f;
 	s = yoffs * 80;
 	crtc_write(CRTC_START_H, s >> 8);
 	crtc_write(CRTC_START_L, s);
@@ -53,9 +53,9 @@ void vga_clearline(int row)
 	ptr = (uint16_t*)0xb8000 + row * 80;
 	memset16(ptr, attr, 80);
 
-	if(row - 25 >= 0) {
+	if(row - 32 >= 0) {
 		/* write a copy to wrap-around future scrolling */
-		ptr -= 80 * 25;
+		ptr -= 80 * 32;
 		memset16(ptr, attr, 80);
 	}
 }
@@ -69,9 +69,9 @@ void vga_drawchar(int x, int y, int c)
 	ptr = (uint16_t*)0xb8000 + y * 80 + x;
 	*ptr = val;
 
-	if(y - 25 >= 0) {
+	if(y - 32 >= 0) {
 		/* write a copy to wrap-around future scrolling */
-		ptr -= 80 * 25;
+		ptr -= 80 * 32;
 		*ptr = val;
 	}
 }