CL-GD5429 improvements :

- Support >8 bpp on RAMDAC
- Support 16-bit pixel depth on blitter
- Support 16-bit pixel depth on write modes 4/5
- Support blitter on PIO
- Support interlaced modes
- Extended size of graphics controller register array to prevent out-of-bounds accesses

src/vid_svga.h

@@ -4,7 +4,7 @@ typedef struct svga_t
         
         uint8_t crtcreg;
         uint8_t crtc[128];
-        uint8_t gdcreg[16];
+        uint8_t gdcreg[64];
         int gdcaddr;
         uint8_t attrregs[32];
         int attraddr, attrff;