diff --git a/Cart_Reader/2600.ino b/Cart_Reader/2600.ino
index 0cebdb5..e0f911a 100644
--- a/Cart_Reader/2600.ino
+++ b/Cart_Reader/2600.ino
@@ -41,13 +41,14 @@ static const byte PROGMEM a2600mapsize[] = {
   0x0A, 2,  // "UA" UA Ltd 8K
   0x3E, 5,  // Tigervision 32K with 32K RAM
   0x07, 6,  // X07 64K ROM
+  0xDF, 7,  // "DFSC" Penult 128K ROM with 32K RAM
 };
 
 byte a2600mapcount = (sizeof(a2600mapsize) / sizeof(a2600mapsize[0])) / 2;
 byte a2600mapselect;
 int a2600index;
 
-byte a2600[] = { 2, 4, 8, 12, 16, 32, 64 };
+byte a2600[] = { 2, 4, 8, 12, 16, 32, 64, 128 };
 byte a2600mapper = 0;
 byte a2600size;
 
@@ -518,6 +519,17 @@ void readROM_2600() {
         readData_2600(0x080D | (x << 4));
         readSegment_2600(0x1000, 0x2000);
       }
+      break;
+
+   case 0xDF:  // DFSC 128K
+      for (int x = 0; x < 0x20; x++) {
+        readData_2600(0x1FC0 + x);
+        readSegment_2600(0x1000, 0x1FBF);
+      }
+      break;
+
+    default:
+      break;
   }
   myFile.close();
 
@@ -555,6 +567,8 @@ void println_Mapper2600(byte mapper) {
     println_Msg(F("TP"));
   else if (mapper == 0x07)
     println_Msg(F("X07"));
+  else if (mapper == 0xDF)
+    println_Msg(F("DFSC"));
   else
     println_Msg(mapper, HEX);
 #else
@@ -578,6 +592,8 @@ void println_Mapper2600(byte mapper) {
     Serial.println(F("TP"));
   else if (mapper == 0x07)
     Serial.println(F("X07"));
+  else if (mapper == 0xDF)
+    Serial.println(F("DFSC"));
   else
     Serial.println(mapper, HEX);
 #endif
@@ -586,7 +602,7 @@ void println_Mapper2600(byte mapper) {
 void checkStatus_2600() {
   EEPROM_readAnything(7, a2600mapper);
   EEPROM_readAnything(8, a2600size);
-  if (a2600size > 6) {
+  if (a2600size > 7) {
     a2600size = 1;  // default 4KB
     EEPROM_writeAnything(8, a2600size);
   }
@@ -670,7 +686,8 @@ setmapper:
   Serial.println(F("17 = UA [UA Ltd]"));
   Serial.println(F("18 = 3E [Tigervision 32K \w RAM]"));
   Serial.println(F("19 = 07 [X07 64K]"));
-  Serial.print(F("Enter Mapper [0-19]: "));
+  Serial.println(F("20 = DFSC [Penult 128K]"));
+  Serial.print(F("Enter Mapper [0-20]: "));
   while (Serial.available() == 0) {}
   newmap = Serial.readStringUntil('\n');
   Serial.println(newmap);
diff --git a/Cart_Reader/Config.h b/Cart_Reader/Config.h
index dddebe6..7b88178 100644
--- a/Cart_Reader/Config.h
+++ b/Cart_Reader/Config.h
@@ -70,7 +70,7 @@
 /* [ Atari 2600 --------------------------------------------------- ]
 */
 
-//#define ENABLE_2600
+#define ENABLE_2600
 
 /****/