diff --git a/Makefile b/Makefile
index 71008ed..ea0c492 100644
--- a/Makefile
+++ b/Makefile
@@ -67,7 +67,6 @@ firmware-build: firmware/*.mk firmware/**/*.c firmware/**/*.h firmware/**/**/*.r
 	cd firmware && $(MAKE) -f ansible.mk
 
 firmware-clean:
-	rm -rfv firmware/build
 	rm -fv res/firmware/*.dll
 	rm -fv res/firmware/*.dylib
 	rm -fv res/firmware/*.so
diff --git a/firmware/common.mk b/firmware/common.mk
index bc22d1b..60a9536 100644
--- a/firmware/common.mk
+++ b/firmware/common.mk
@@ -2,6 +2,7 @@ SHELL := /bin/bash -O extglob
 RACK_DIR ?= ../../..
 
 TARGET_DIR := ../res/firmware/
+BUILD_DIR := ../build/firmware/$(TARGET_NAME)
 
 FLAGS += \
 	-DDEBUG \
@@ -33,7 +34,7 @@ ifeq ($(ARCH_WIN), 1)
 	TARGET = $(TARGET_DIR)$(TARGET_NAME).dll
 endif
 
-include $(RACK_DIR)/compile.mk
+include compile.mk
 
 all: $(TARGET)
 
diff --git a/firmware/compile.mk b/firmware/compile.mk
new file mode 100644
index 0000000..3b19f4f
--- /dev/null
+++ b/firmware/compile.mk
@@ -0,0 +1,114 @@
+# Rack SDK compile.mk modified to support configurable build products folder
+
+ifndef RACK_DIR
+$(error RACK_DIR is not defined)
+endif
+
+include $(RACK_DIR)/arch.mk
+
+BUILD_DIR ?= build
+OBJCOPY ?= objcopy
+STRIP ?= strip
+INSTALL_NAME_TOOL ?= install_name_tool
+OTOOL ?= otool
+
+# Generate dependency files alongside the object files
+FLAGS += -MMD -MP
+# Debugger symbols. These are removed with `strip`.
+FLAGS += -g
+# Optimization
+FLAGS += -O3 -funsafe-math-optimizations -fno-omit-frame-pointer
+# Warnings
+FLAGS += -Wall -Wextra -Wno-unused-parameter
+# C++ standard
+CXXFLAGS += -std=c++11
+
+# Define compiler/linker target if cross-compiling
+ifdef CROSS_COMPILE
+	FLAGS += --target=$(MACHINE)
+	LDFLAGS += --target=$(MACHINE)
+endif
+
+# Architecture-independent flags
+ifdef ARCH_X64
+	FLAGS += -DARCH_X64
+	FLAGS += -march=nehalem
+endif
+ifdef ARCH_ARM64
+	FLAGS += -DARCH_ARM64
+	FLAGS += -march=armv8-a+fp+simd
+endif
+
+ifdef ARCH_LIN
+	FLAGS += -DARCH_LIN
+	CXXFLAGS += -Wsuggest-override
+endif
+ifdef ARCH_MAC
+	FLAGS += -DARCH_MAC
+	CXXFLAGS += -stdlib=libc++
+	LDFLAGS += -stdlib=libc++
+	MAC_SDK_FLAGS := -mmacosx-version-min=10.9
+	FLAGS += $(MAC_SDK_FLAGS)
+	LDFLAGS += $(MAC_SDK_FLAGS)
+endif
+ifdef ARCH_WIN
+	FLAGS += -DARCH_WIN
+	FLAGS += -D_USE_MATH_DEFINES
+	FLAGS += -municode
+	CXXFLAGS += -Wsuggest-override
+endif
+
+# Allow *appending* rather than prepending to common flags.
+# This is useful to force-redefine compiler settings instead of merely setting defaults that may be overwritten.
+FLAGS += $(EXTRA_FLAGS)
+CFLAGS += $(EXTRA_CFLAGS)
+CXXFLAGS += $(EXTRA_CXXFLAGS)
+LDFLAGS += $(EXTRA_LDFLAGS)
+
+# Apply FLAGS to language-specific flags
+CFLAGS += $(FLAGS)
+CXXFLAGS += $(FLAGS)
+
+# Derive object files from sources and place them before user-defined objects
+OBJECTS := $(patsubst %, $(BUILD_DIR)/%.o, $(SOURCES)) $(OBJECTS)
+OBJECTS += $(patsubst %, $(BUILD_DIR)/%.bin.o, $(BINARIES))
+DEPENDENCIES := $(patsubst %, $(BUILD_DIR)/%.d, $(SOURCES))
+
+# Final targets
+
+$(TARGET): $(OBJECTS)
+	$(CXX) -o $@ $^ $(LDFLAGS)
+
+-include $(DEPENDENCIES)
+
+$(BUILD_DIR)/%.c.o: %.c
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(BUILD_DIR)/%.cpp.o: %.cpp
+	@mkdir -p $(@D)
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+$(BUILD_DIR)/%.cc.o: %.cc
+	@mkdir -p $(@D)
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+$(BUILD_DIR)/%.m.o: %.m
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+$(BUILD_DIR)/%.bin.o: %
+	@mkdir -p $(@D)
+ifdef ARCH_LIN
+	$(OBJCOPY) -I binary -O elf64-x86-64 -B i386:x86-64 --rename-section .data=.rodata,alloc,load,readonly,data,contents $< $@
+endif
+ifdef ARCH_WIN
+	$(OBJCOPY) -I binary -O pe-x86-64 -B i386:x86-64 --rename-section .data=.rodata,alloc,load,readonly,data,contents $< $@
+endif
+ifdef ARCH_MAC
+	@# Apple makes this needlessly complicated, so just generate a C file with an array.
+	xxd -i $< | $(CC) $(MAC_SDK_FLAGS) -c -o $@ -xc -
+endif
+
+$(BUILD_DIR)/%.html: %.md
+	markdown $< > $@
diff --git a/firmware/mock_hardware/modules/teletype/adapter_teletype.c b/firmware/mock_hardware/modules/teletype/adapter_teletype.c
index f06a80e..a8bc4b8 100644
--- a/firmware/mock_hardware/modules/teletype/adapter_teletype.c
+++ b/firmware/mock_hardware/modules/teletype/adapter_teletype.c
@@ -8,7 +8,7 @@
 #include "module/globals.h"
 #include "module/live_mode.h"
 #include "module/preset_w_mode.h"
-#include "src/serialize.h"
+#include "src/scene_serialization.h"
 #include "src/teletype_io.h"
 #include "types.h"
 
@@ -62,8 +62,16 @@ void fake_flash_read(scene_state_t* src_scene, scene_state_t* dest_scene,
     uint8_t init_i2c_op_address)
 {
     memcpy(ss_scripts_ptr(dest_scene), ss_scripts_ptr(src_scene),
+
+// handle difference in macros between TT 5 and 4
+#ifdef EDITABLE_SCRIPT_COUNT
+        ss_scripts_size(EDITABLE_SCRIPT_COUNT)
+#else
         // Exclude size of TEMP script as above
-        ss_scripts_size() - sizeof(scene_script_t));
+        ss_scripts_size() - sizeof(scene_script_t)
+#endif
+
+    );
 
     if (init_pattern)
     {
@@ -77,7 +85,13 @@ void fake_flash_read(scene_state_t* src_scene, scene_state_t* dest_scene,
     memcpy(dest_text, src_text, SCENE_TEXT_LINES * SCENE_TEXT_CHARS);
     // need to reset timestamps
     uint32_t ticks = tele_get_ticks();
+
+// handle difference in macros between TT 5 and 4
+#ifdef TOTAL_SCRIPT_COUNT
+    for (size_t i = 0; i < TOTAL_SCRIPT_COUNT; i++)
+#else
     for (size_t i = 0; i < TEMP_SCRIPT; i++)
+#endif
         dest_scene->scripts[i].last_time = ticks;
     dest_scene->variables.time = 0;
 
diff --git a/firmware/teletype4 b/firmware/teletype4
index 407c6e7..a34da87 160000
--- a/firmware/teletype4
+++ b/firmware/teletype4
@@ -1 +1 @@
-Subproject commit 407c6e720ad2b080917f266c98996014e1671d36
+Subproject commit a34da87afb779b993cd0a6bce4e6102cd35c4a95