diff --git a/flash.h b/flash.h
index 086764f..ccb3665 100644
--- a/flash.h
+++ b/flash.h
@@ -80,7 +80,10 @@
 #define MSYSTEMS_MD2802   0x30	/* hmm -- both 0x30 */
 
 #define SM_ID		  0x40  /* SyncMOS ID */
-#define S29C51002T	  0x02
+#define S29C51001T	  0x01  /* SyncMOS S29C51001T/B */
+#define S29C51002T	  0x02  /* SyncMOS S29C51002T/B */
+#define S29C51004T	  0x03  /* SyncMOS S29C51004T/B */
+#define S29C31004T	  0x63  /* SyncMOS S29C31004T */
 
 extern void myusec_delay(int time);
 extern void myusec_calibrate_delay();
diff --git a/flashchips.c b/flashchips.c
index 1400918..c1ee4eb 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -114,8 +114,14 @@
 #endif
 	{"LHF00L04",	SHARP_ID,		SHARP_LHF00L04,		NULL, 1024, 64 * 1024,
 	 probe_lhf00l04, erase_lhf00l04,	write_lhf00l04,	NULL},
+	{"S29C51001T", 	SM_ID, 	S29C51001T,	NULL, 128, 128,
+	 probe_jedec,	erase_chip_jedec, write_49f002, NULL},
 	{"S29C51002T", 	SM_ID, 	S29C51002T,	NULL, 256, 128,
 	 probe_jedec,	erase_chip_jedec, write_49f002, NULL},
+	{"S29C51004T", 	SM_ID, 	S29C51004T,	NULL, 512, 128,
+	 probe_jedec,	erase_chip_jedec, write_49f002, NULL},
+	{"S29C31004T", 	SM_ID, 	S29C31004T,	NULL, 512, 128,
+	 probe_jedec,	erase_chip_jedec, write_49f002, NULL},
 	{NULL,}
 };