Mode X test

tests/pc/vga/L47-7.C

@@ -0,0 +1,25 @@
+/* Program to demonstrate mode X (320x240, 256-colors) rectangle
+   fill by drawing adjacent 20x20 rectangles in successive colors from
+   0 on up across and down the screen
+*/
+#include <conio.h>
+#include <dos.h>
+
+void Set320x240Mode(void);
+void FillRectangleX(int, int, int, int, unsigned int, int);
+
+void main() {
+	int i,j;
+	union REGS regset;
+
+	Set320x240Mode();
+	FillRectangleX(0,0,320,240,0,0); /* clear the screen to black */
+	for (j = 1; j < 220; j += 21) {
+		for (i = 1; i < 300; i += 21) {
+			FillRectangleX(i, j, i+20, j+20, 0, ((j/21*15)+i/21) & 0xFF);
+		}
+	}
+	getch();
+	regset.x.ax = 0x0003;   /* switch back to text mode and done */
+	int86(0x10, &regset, &regset);
+}