Split up pins to make it more manageable

Hopefully this is helpful to organization and future expansion….

Marlin/pins_RAMPS_OLD.h

@@ -0,0 +1,69 @@
+/**
+ * Arduino Mega with RAMPS v1.0, v1.1, v1.2 pin assignments
+ */
+
+#if !defined(__AVR_ATmega1280__) && !defined(__AVR_ATmega2560__)
+  #error Oops!  Make sure you have 'Arduino Mega' selected from the 'Tools -> Boards' menu.
+#endif
+
+// Uncomment the following line for RAMPS v1.0
+//#define RAMPS_V_1_0
+
+#define X_STEP_PIN         26
+#define X_DIR_PIN          28
+#define X_ENABLE_PIN       24
+#define X_MIN_PIN           3
+#define X_MAX_PIN          -1    //2
+
+#define Y_STEP_PIN         38
+#define Y_DIR_PIN          40
+#define Y_ENABLE_PIN       36
+#define Y_MIN_PIN          16
+#define Y_MAX_PIN          -1    //17
+
+#define Z_STEP_PIN         44
+#define Z_DIR_PIN          46
+#define Z_ENABLE_PIN       42
+#define Z_MIN_PIN          18
+#define Z_MAX_PIN          -1    //19
+
+#define E0_STEP_PIN         32
+#define E0_DIR_PIN          34
+#define E0_ENABLE_PIN       30
+
+#define SDPOWER            48
+#define SDSS               53
+#define LED_PIN            13
+#define PS_ON_PIN          -1
+#define KILL_PIN           -1
+
+#ifdef RAMPS_V_1_0 // RAMPS_V_1_0
+  #define HEATER_0_PIN     12    // RAMPS 1.0
+  #define HEATER_BED_PIN   -1    // RAMPS 1.0
+  #define FAN_PIN          11    // RAMPS 1.0
+#else // RAMPS_V_1_1 or RAMPS_V_1_2
+  #define HEATER_0_PIN     10    // RAMPS 1.1
+  #define HEATER_BED_PIN    8    // RAMPS 1.1
+  #define FAN_PIN           9    // RAMPS 1.1
+#endif
+
+#define HEATER_1_PIN        -1
+#define HEATER_2_PIN        -1
+#define TEMP_0_PIN          2    // MUST USE ANALOG INPUT NUMBERING NOT DIGITAL OUTPUT NUMBERING!!!!!!!!!
+#define TEMP_1_PIN          -1
+#define TEMP_2_PIN          -1
+#define TEMP_BED_PIN        1    // MUST USE ANALOG INPUT NUMBERING NOT DIGITAL OUTPUT NUMBERING!!!!!!!!!
+
+// SPI for Max6675 Thermocouple
+#ifndef SDSUPPORT
+  #define MAX6675_SS       66// Do not use pin 53 if there is even the remote possibility of using Display/SD card
+#else
+  #define MAX6675_SS       66// Do not use pin 49 as this is tied to the switch inside the SD card socket to detect if there is an SD card present
+#endif
+
+#ifndef SDSUPPORT
+  // these pins are defined in the SD library if building with SD support
+  #define SCK_PIN          52
+  #define MISO_PIN         50
+  #define MOSI_PIN         51
+#endif