diff --git a/Marlin/src/core/boards.h b/Marlin/src/core/boards.h
index da7d15ec33..605f2e74a4 100644
--- a/Marlin/src/core/boards.h
+++ b/Marlin/src/core/boards.h
@@ -109,6 +109,9 @@
#define BOARD_COPYMASTER_3D 1153 // Copymaster 3D
#define BOARD_ORTUR_4 1154 // Ortur 4
#define BOARD_TENLOG_D3_HERO 1155 // Tenlog D3 Hero IDEX printer
+#define BOARD_RAMPS_S_12_EEFB 1156 // Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Fan, Bed)
+#define BOARD_RAMPS_S_12_EEEB 1157 // Ramps S 1.2 by Sakul.cz (Power outputs: Hotend0, Hotend1, Hotend2, Bed)
+#define BOARD_RAMPS_S_12_EFFB 1158 // Ramps S 1.2 by Sakul.cz (Power outputs: Hotend, Fan0, Fan1, Bed)
//
// RAMBo and derivatives
diff --git a/Marlin/src/pins/pins.h b/Marlin/src/pins/pins.h
index 5259b147fb..1e2da66228 100644
--- a/Marlin/src/pins/pins.h
+++ b/Marlin/src/pins/pins.h
@@ -207,6 +207,12 @@
#include "ramps/pins_TENLOG_D3_HERO.h" // ATmega2560 env:mega2560
#elif MB(MKS_GEN_L_V21)
#include "ramps/pins_MKS_GEN_L_V21.h" // ATmega2560 env:mega2560
+#elif MB(RAMPS_S_12_EEFB)
+ #include "ramps/pins_RAMPS_S_12.h" // ATmega2560 env:mega2560
+#elif MB(RAMPS_S_12_EEEB)
+ #include "ramps/pins_RAMPS_S_12.h" // ATmega2560 env:mega2560
+#elif MB(RAMPS_S_12_EFFB)
+ #include "ramps/pins_RAMPS_S_12.h" // ATmega2560 env:mega2560
//
// RAMBo and derivatives
diff --git a/Marlin/src/pins/ramps/pins_RAMPS.h b/Marlin/src/pins/ramps/pins_RAMPS.h
index c8578f2fa1..69a80d6b27 100644
--- a/Marlin/src/pins/ramps/pins_RAMPS.h
+++ b/Marlin/src/pins/ramps/pins_RAMPS.h
@@ -52,7 +52,7 @@
#endif
#if NOT_TARGET(IS_RAMPS_SMART, IS_RAMPS_DUO, IS_RAMPS4DUE, TARGET_LPC1768, __AVR_ATmega1280__, __AVR_ATmega2560__)
- #error "Oops! Select 'Arduino/Genuino Mega or Mega 2560' in 'Tools > Board.'"
+ #error "Oops! Select 'Arduino/Genuino Mega or Mega 2560' (or other appropriate target) in 'Tools > Board.'"
#endif
// Custom flags and defines for the build
diff --git a/Marlin/src/pins/ramps/pins_RAMPS_S_12.h b/Marlin/src/pins/ramps/pins_RAMPS_S_12.h
new file mode 100644
index 0000000000..1e063c269d
--- /dev/null
+++ b/Marlin/src/pins/ramps/pins_RAMPS_S_12.h
@@ -0,0 +1,275 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+#pragma once
+
+/**
+ * Arduino Mega with RAMPS-S v1.2 by Sakul.cz pin assignments
+ * Written by Michal Rábek
+ *
+ * Applies to the following boards:
+ *
+ * BOARD_RAMPS_S_12_EEFB Ramps S 1.2 (Hotend0, Hotend1, Fan, Bed)
+ * BOARD_RAMPS_S_12_EEEB Ramps S 1.2 (Hotend0, Hotend1, Hotend2, Bed)
+ * BOARD_RAMPS_S_12_EFFB Ramps S 1.2 (Hotend, Fan0, Fan1, Bed)
+ *
+ * Other pins_MYBOARD.h files may override these defaults
+ */
+
+#if NOT_TARGET(__AVR_ATmega1280__, __AVR_ATmega2560__)
+ #error "Oops! Select 'Arduino/Genuino Mega or Mega 2560' in 'Tools > Board.'"
+#endif
+
+// Custom flags and defines for the build
+//#define BOARD_CUSTOM_BUILD_FLAGS -D__FOO__
+
+#ifndef BOARD_INFO_NAME
+ #define BOARD_INFO_NAME "RAMPS S 1.2"
+#endif
+
+//
+// Servos
+//
+#ifndef SERVO0_PIN
+ #define SERVO0_PIN 10
+#endif
+#ifndef SERVO1_PIN
+ #define SERVO1_PIN 11
+#endif
+#ifndef SERVO2_PIN
+ #define SERVO2_PIN 12
+#endif
+#ifndef SERVO3_PIN
+ #define SERVO3_PIN 44
+#endif
+
+//
+// Limit Switches
+//
+#ifndef X_STOP_PIN
+ #ifndef X_MIN_PIN
+ #define X_MIN_PIN 37
+ #endif
+ #ifndef X_MAX_PIN
+ #define X_MAX_PIN 36
+ #endif
+#endif
+#ifndef Y_STOP_PIN
+ #ifndef Y_MIN_PIN
+ #define Y_MIN_PIN 35
+ #endif
+ #ifndef Y_MAX_PIN
+ #define Y_MAX_PIN 34
+ #endif
+#endif
+#ifndef Z_STOP_PIN
+ #ifndef Z_MIN_PIN
+ #define Z_MIN_PIN 33
+ #endif
+ #ifndef Z_MAX_PIN
+ #define Z_MAX_PIN 32
+ #endif
+#endif
+
+//
+// Z Probe (when not Z_MIN_PIN)
+//
+#ifndef Z_MIN_PROBE_PIN
+ #define Z_MIN_PROBE_PIN 5
+#endif
+
+//
+// Filament Runout Sensor
+//
+#ifndef FIL_RUNOUT_PIN
+ #define FIL_RUNOUT_PIN 44 // RAMPS_S S3 on the servos connector
+#endif
+
+//
+// Steppers
+//
+#define X_STEP_PIN 17
+#define X_DIR_PIN 16
+#define X_ENABLE_PIN 48
+
+#define Y_STEP_PIN 54
+#define Y_DIR_PIN 47
+#define Y_ENABLE_PIN 55
+
+#ifndef Z_STEP_PIN
+ #define Z_STEP_PIN 57
+#endif
+#define Z_DIR_PIN 56
+#define Z_ENABLE_PIN 62
+
+#define E0_STEP_PIN 23
+#define E0_DIR_PIN 22
+#define E0_ENABLE_PIN 24
+
+#define E1_STEP_PIN 26
+#define E1_DIR_PIN 25
+#define E1_ENABLE_PIN 27
+
+#define E2_STEP_PIN 29
+#define E2_DIR_PIN 28
+#define E2_ENABLE_PIN 39
+
+//
+// Temperature Sensors
+//
+#ifndef TEMP_0_PIN
+ #define TEMP_0_PIN 15 // Analog Input
+#endif
+#ifndef TEMP_1_PIN
+ #define TEMP_1_PIN 14 // Analog Input
+#endif
+#ifndef TEMP_2_PIN
+ #define TEMP_2_PIN 13 // Analog Input
+#endif
+#ifndef TEMP_3_PIN
+ #define TEMP_3_PIN 12 // Analog Input
+#endif
+#ifndef TEMP_BED_PIN
+ #define TEMP_BED_PIN 11 // Analog Input
+#endif
+
+//
+// Heaters / Fans
+//
+#ifndef MOSFET_D_PIN
+ #define MOSFET_D_PIN -1
+#endif
+#ifndef RAMPS_S_HE_0
+ #define RAMPS_S_HE_0 2
+#endif
+#ifndef RAMPS_S_HE_1
+ #define RAMPS_S_HE_1 3
+#endif
+#ifndef RAMPS_S_HE_2
+ #define RAMPS_S_HE_2 6
+#endif
+
+#define HEATER_BED_PIN 9
+
+#define HEATER_0_PIN RAMPS_S_HE_0
+
+#if MB(RAMPS_S_12_EEFB) // Hotend0, Hotend1, Fan, Bed
+ #define HEATER_1_PIN RAMPS_S_HE_1
+ #define FAN_PIN RAMPS_S_HE_2
+#elif MB(RAMPS_S_12_EEEB) // Hotend0, Hotend1, Hotend2, Bed
+ #define HEATER_1_PIN RAMPS_S_HE_1
+ #define HEATER_2_PIN RAMPS_S_HE_2
+#elif MB(RAMPS_S_12_EFFB) // Hotend, Fan0, Fan1, Bed
+ #define FAN_PIN RAMPS_S_HE_1
+ #define FAN1_PIN RAMPS_S_HE_2
+#endif
+
+//
+// Misc. Functions
+//
+#define SDSS 53
+#define LED_PIN 13
+
+#ifndef KILL_PIN
+ #define KILL_PIN 46
+#endif
+
+#ifndef FILWIDTH_PIN
+ #define FILWIDTH_PIN 60 // Analog Input on EXTEND
+#endif
+
+#ifndef PS_ON_PIN
+ #define PS_ON_PIN 12 // RAMPS_S S2 on the servos connector
+#endif
+
+#if ENABLED(CASE_LIGHT_ENABLE) && !defined(CASE_LIGHT_PIN) && !defined(SPINDLE_LASER_ENA_PIN)
+ #if NUM_SERVOS <= 1 // Prefer the servo connector
+ #define CASE_LIGHT_PIN 12 // Hardware PWM (RAMPS_S S1 on the servos connector)
+ #elif HAS_FREE_AUX2_PINS
+ #define CASE_LIGHT_PIN 44 // Hardware PWM
+ #endif
+#endif
+
+//
+// M3/M4/M5 - Spindle/Laser Control
+//
+#if HAS_CUTTER && !defined(SPINDLE_LASER_ENA_PIN)
+ #define SPINDLE_LASER_ENA_PIN 4 // Pullup or pulldown!
+ #define SPINDLE_LASER_PWM_PIN 6 // Hardware PWM
+ #define SPINDLE_DIR_PIN 5
+#endif
+
+//
+// TMC software SPI
+//
+#if ENABLED(TMC_USE_SW_SPI)
+ #ifndef TMC_SW_MOSI
+ #define TMC_SW_MOSI 51
+ #endif
+ #ifndef TMC_SW_MISO
+ #define TMC_SW_MISO 50
+ #endif
+ #ifndef TMC_SW_SCK
+ #define TMC_SW_SCK 53
+ #endif
+#endif
+
+//
+// Průša i3 MK2 Multiplexer Support
+//
+#ifndef E_MUX0_PIN
+ #define E_MUX0_PIN 29 // E2_STEP_PIN
+#endif
+#ifndef E_MUX1_PIN
+ #define E_MUX1_PIN 28 // E2_DIR_PIN
+#endif
+#ifndef E_MUX2_PIN
+ #define E_MUX2_PIN 39 // E2_ENABLE_PIN
+#endif
+
+//////////////////////////
+// LCDs and Controllers //
+//////////////////////////
+
+//
+// LCD Display output pins
+//
+#if HAS_WIRED_LCD
+ #define BEEPER_PIN 45
+ #define LCD_PINS_RS 19
+ #define LCD_PINS_ENABLE 49
+ #define LCD_PINS_D4 18
+ #define LCD_PINS_D5 30
+ #define LCD_PINS_D6 41
+ #define LCD_PINS_D7 31
+ #ifndef SD_DETECT_PIN
+ #define SD_DETECT_PIN 38
+ #endif
+#endif
+
+//
+// LCD Display input pins
+//
+#if IS_NEWPANEL
+ #define BTN_EN1 40
+ #define BTN_EN2 42
+ #define BTN_ENC 43
+#endif