CRTC on CGA-like graphics chips is now on the entire 3D0 to 3D7 port range, fixes scrolling in some old games.

src/video/vid_cga.c

@@ -58,6 +58,9 @@ cga_out(uint16_t addr, uint8_t val, void *p)
     cga_t *cga = (cga_t *) p;
     uint8_t old;
 
+    if ((addr >= 0x3d0) && (addr <= 0x3d7))
+	addr = (addr & 0xff9) | 0x004;
+
     switch (addr) {
 	case 0x3D4:
 		cga->crtcreg = val & 31;
@@ -100,6 +103,9 @@ cga_in(uint16_t addr, void *p)
 
     uint8_t ret = 0xff;
 
+    if ((addr >= 0x3d0) && (addr <= 0x3d7))
+	addr = (addr & 0xff9) | 0x004;
+
     switch (addr) {
 	case 0x3D4:
 		ret = cga->crtcreg;