+#define CMD_IOSEQ 0xc4 /* perform i/o ops: count[2], [type[1], addr[3], data[{0,1,2,4}]]* */
+#define CMD_LOADSTATE 0xc5 /* load PD state: vram[64k], cram[128], vsram[128], vdp[32] */
+#define CMD_VRAM_RECV 0xc6 /* recv from MD: vram[64k] */
+#define CMD_TEST 0xc7 /* test code */