diff --git a/examples/demos/stars/Makefile b/examples/demos/stars/Makefile
index 1b1d068..47e0096 100644
--- a/examples/demos/stars/Makefile
+++ b/examples/demos/stars/Makefile
@@ -1,13 +1,15 @@
-# Makefile for building the random pixel demo
-# Compiles random_pixels.has -> random_pixels.s -> random_pixels.o
+# Makefile for building demos in examples/demos/stars
+# Compiles each .has file to build/<name>.s -> build/<name>.o -> build/<name>.exe
 # Links with library object files from build/
 
 .SUFFIXES:
 
-MAKEFILE_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
-PROJ_ROOT := $(abspath $(MAKEFILE_DIR)../../..)
+PROJ_ROOT := ../../..
 
-HASC := cd $(PROJ_ROOT) && .venv/bin/python -m hasc.cli
+# Resolve compiler runner from project root.
+# Prefer `venv`, then `.venv`, then fallback to system python3.
+PYTHON_BIN := $(if $(wildcard $(PROJ_ROOT)/venv/bin/python),venv/bin/python,$(if $(wildcard $(PROJ_ROOT)/.venv/bin/python),.venv/bin/python,python3))
+HASC := cd "$(PROJ_ROOT)" && "$(PYTHON_BIN)" -m hasc.cli
 VASM := vasmm68k_mot
 VLINK := vlink
 
@@ -15,10 +17,11 @@ LIB_DIR := ../../../lib
 BUILD_DIR := ../../../build
 SRC_DIR := .
 
-HAS_SOURCE := random_pixels.has
-ASM_SOURCE := $(BUILD_DIR)/random_pixels.s
-MAIN_OBJ := $(BUILD_DIR)/random_pixels.o
-EXE_FILE := $(BUILD_DIR)/random_pixels.exe
+HAS_SOURCES := $(wildcard $(SRC_DIR)/*.has)
+DEMO_NAMES := $(basename $(notdir $(HAS_SOURCES)))
+ASM_SOURCES := $(addprefix $(BUILD_DIR)/,$(addsuffix .s,$(DEMO_NAMES)))
+MAIN_OBJS := $(addprefix $(BUILD_DIR)/,$(addsuffix .o,$(DEMO_NAMES)))
+EXE_FILES := $(addprefix $(BUILD_DIR)/,$(addsuffix .exe,$(DEMO_NAMES)))
 
 LIB_OBJS := $(BUILD_DIR)/graphics.o \
             $(BUILD_DIR)/helpers.o \
@@ -27,27 +30,31 @@ LIB_OBJS := $(BUILD_DIR)/graphics.o \
             $(BUILD_DIR)/input.o \
             $(BUILD_DIR)/heap.o \
             $(BUILD_DIR)/bob.o \
+			$(BUILD_DIR)/font8x8.o \
             $(BUILD_DIR)/takeover.o
 
 VASM_FLAGS := -m68000 -Fhunk -kick1hunks -I$(LIB_DIR)
 VLINK_FLAGS := -bamigahunk -Bstatic
 
-.PHONY: all clean run compile assemble link
+.PHONY: all clean run compile assemble link list amiga run-vamos
 
-all: $(EXE_FILE)
+all: $(EXE_FILES)
+
+list:
+	@echo "Demos in $(SRC_DIR): $(DEMO_NAMES)"
 
 $(BUILD_DIR):
 	@mkdir -p $(BUILD_DIR)
 
-$(EXE_FILE): $(MAIN_OBJ) $(LIB_OBJS)
-	@echo "Linking demo + libraries -> $(notdir $(EXE_FILE))"
+$(BUILD_DIR)/%.exe: $(BUILD_DIR)/%.o $(LIB_OBJS)
+	@echo "Linking demo + libraries -> $(notdir $@)"
 	@which $(VLINK) > /dev/null || (echo "Error: $(VLINK) not found in PATH"; exit 1)
 	$(VLINK) $(VLINK_FLAGS) $^ -o $@
 
-$(MAIN_OBJ): $(ASM_SOURCE) | $(BUILD_DIR)
+$(BUILD_DIR)/%.o: $(BUILD_DIR)/%.s | $(BUILD_DIR)
 	@echo "Assembling $(notdir $<) -> $(notdir $@)"
 	@which $(VASM) > /dev/null || (echo "Error: $(VASM) not found in PATH"; exit 1)
-	$(VASM) $(VASM_FLAGS) -L $(BUILD_DIR)/random_pixels.lst -o $@ $<
+	$(VASM) $(VASM_FLAGS) -L $(BUILD_DIR)/$*.lst -o $@ $<
 
 $(BUILD_DIR)/graphics.o: $(LIB_DIR)/graphics.s | $(BUILD_DIR)
 	@echo "Assembling graphics.s -> $(notdir $@)"
@@ -81,17 +88,39 @@ $(BUILD_DIR)/bob.o: $(LIB_DIR)/bob.s | $(BUILD_DIR)
 	@echo "Assembling bob.s -> $(notdir $@)"
 	$(VASM) $(VASM_FLAGS) -L $(BUILD_DIR)/bob.lst -o $@ $<
 
-$(ASM_SOURCE): $(HAS_SOURCE) | $(BUILD_DIR)
-	@echo "Compiling $(HAS_SOURCE) -> $(notdir $@)"
+$(BUILD_DIR)/font8x8.o: $(LIB_DIR)/font8x8.s | $(BUILD_DIR)
+	@echo "Assembling font8x8.s -> $(notdir $@)"
+	$(VASM) $(VASM_FLAGS) -L $(BUILD_DIR)/font8x8.lst -o $@ $<
+
+
+$(BUILD_DIR)/%.s: %.has | $(BUILD_DIR)
+	@echo "Compiling $< -> $(notdir $@)"
 	@mkdir -p $(dir $@)
-	$(HASC) examples/demos/stars/$< -o build/random_pixels.s
+	$(HASC) examples/demos/stars/$< -o build/$*.s
 
-compile: $(ASM_SOURCE)
-assemble: $(MAIN_OBJ)
-link: $(EXE_FILE)
+compile: $(ASM_SOURCES)
+assemble: $(MAIN_OBJS)
+link: $(EXE_FILES)
 
 clean:
-	rm -rf $(BUILD_DIR)/random_pixels.o $(BUILD_DIR)/random_pixels.s $(BUILD_DIR)/random_pixels.exe $(BUILD_DIR)/random_pixels.lst
-
-run: $(EXE_FILE)
-	./$(EXE_FILE)
+	rm -rf $(ASM_SOURCES) $(MAIN_OBJS) $(EXE_FILES) $(addprefix $(BUILD_DIR)/,$(addsuffix .lst,$(DEMO_NAMES)))
+
+DEMO ?= random_pixels
+TARGET_EXE := $(BUILD_DIR)/$(DEMO).exe
+
+# Build one selected Amiga executable (e.g. `make amiga DEMO=Texts`).
+amiga: $(TARGET_EXE)
+	@echo "Amiga executable ready: $(TARGET_EXE)"
+
+# Run the Amiga executable via vamos when available.
+run-vamos: $(TARGET_EXE)
+	@if which vamos > /dev/null; then \
+		echo "Running $(TARGET_EXE) with vamos"; \
+		vamos $(TARGET_EXE); \
+	else \
+		echo "vamos not found. Built Amiga executable: $(TARGET_EXE)"; \
+		echo "Run it on Amiga/emulator manually."; \
+	fi
+
+# Keep `run` as alias for Amiga-oriented execution.
+run: run-vamos
diff --git a/examples/demos/stars/Texts.has b/examples/demos/stars/Texts.has
new file mode 100644
index 0000000..ebfc150
--- /dev/null
+++ b/examples/demos/stars/Texts.has
@@ -0,0 +1,126 @@
+#pragma lockreg(a5);
+
+// Visual regression demo for Text/Print in 320x256x32 mode.
+// Stresses cursor handling, newline behavior, wrapping, colors, and font attachment.
+
+extern var fonts: int;
+const KEY_ESC = 69;
+
+code main:
+    extern func SetGraphicsMode(mode: int) -> int;
+    extern func ClearScreen() -> int;
+    extern func SetColor(id: int, col: int) -> int;
+    extern func SetFont(ptr: int) -> int;
+    extern func Text(x: int, y: int, msg: int, color: int) -> int;
+    extern func Print(msg: int, color: int) -> int;
+    extern func UpdateCopperList() -> int;
+    extern func WaitVBlank() -> int;
+    extern func InitKeyboard() -> void;
+    extern func GetKey() -> byte;
+    extern func TakeSystem() -> void;
+    extern func ReleaseSystem() -> void;
+
+    public main;
+
+    asm {
+        jsr TakeSystem
+        jsr main
+        jmp ReleaseSystem
+    }
+
+    proc main() -> int {
+        var running: int = 1;
+        var key: byte;
+        var frame: int = 0;
+        var blink: int = 0;
+
+        if (SetGraphicsMode(0) == -1) {
+            return -1;
+        }
+
+        call InitKeyboard();
+        call SetFont(&fonts);
+        call ClearScreen();
+
+        // Keep palette explicit so color bugs are easy to spot.
+        call SetColor(0, $000);
+        call SetColor(1, $FFF);
+        call SetColor(2, $F80);
+        call SetColor(3, $0F0);
+        call SetColor(4, $08F);
+        call SetColor(5, $FF0);
+        call SetColor(6, $F0F);
+        call SetColor(7, $0FF);
+
+        call Text(1, 1, &title_txt, 2);
+        call Text(1, 2, &info_txt, 3);
+        call Text(1, 4, &phase1_hdr, 5);
+        call Text(1, 5, &phase1_hint, 1);
+
+        // Phase 1: deterministic Print-only block.
+        call Print(&baseline_block, 2);
+
+        call Text(1, 12, &phase2_hdr, 6);
+        call Text(1, 13, &phase2_hint, 1);
+
+        // Phase 2: mixed Print/Text interactions.
+        call Print(&stress_seq_a, 4);
+        call Print(&stress_seq_lf, 6);
+        call Print(&stress_seq_cr, 7);
+        call Text(2, 17, &text_anchor_a, 5);
+        call Text(2, 19, &text_anchor_b, 7);
+        call Print(&post_text_seq, 2);
+        call Print(&wrap_test_seq, 3);
+
+        call Text(1, 30, &exit_hint_txt, 1);
+        call UpdateCopperList();
+
+        while (running == 1) {
+            call WaitVBlank();
+
+            // Small periodic update to keep exercising Text on same line.
+            frame = frame + 1;
+            if (frame == 25) {
+                frame = 0;
+                if (blink == 0) {
+                    blink = 1;
+                    call Text(1, 28, &pulse_a_txt, 4);
+                } else {
+                    blink = 0;
+                    call Text(1, 28, &pulse_b_txt, 6);
+                }
+                call UpdateCopperList();
+            }
+
+            key = GetKey();
+            if (key == KEY_ESC) {
+                running = 0;
+            }
+        }
+
+        return 0;
+    }
+
+data text_data:
+    title_txt.b = "Texts.has - Print/Text Regression Demo", 0
+    info_txt.b = "Mode: 320x256x32 | font: lib/font8x8.s", 0
+
+    phase1_hdr.b = "PHASE 1: BASELINE (PRINT ONLY)", 0
+    phase1_hint.b = "Expected: full labels, stable left edge, no missing first chars.", 0
+    baseline_block.b = 10, "BASE-A: 0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ", 10, "BASE-B: AAAA BBBB CCCC DDDD", 10, "BASE-C: left edge marker -> [#]", 0
+
+    phase2_hdr.b = "PHASE 2: STRESS (PRINT + TEXT MIX)", 0
+    phase2_hint.b = "Expected: Text() anchors do not permanently move Print cursor.", 0
+    stress_seq_a.b = 10, "STRESS-A: mixed cursor test start", 0
+    stress_seq_lf.b = 10, "STRESS-B after LF should start on next line.", 0
+    stress_seq_cr.b = 13, "STRESS-C after CR should also start on next line.", 0
+
+    text_anchor_a.b = "TEXT anchor A at (2,17)", 0
+    text_anchor_b.b = "TEXT anchor B at (2,19)", 0
+    post_text_seq.b = "STRESS-D cursor should continue from STRESS-C, not Text anchors.", 0
+
+    wrap_test_seq.b = "WRAP: 0123456789012345678901234567890123456789 <- end", 0
+
+    pulse_a_txt.b = "Pulse line via Text(): state A", 0
+    pulse_b_txt.b = "Pulse line via Text(): state B", 0
+    exit_hint_txt.b = "Press ESC to exit demo.", 0
diff --git a/examples/msgbox_demo.has b/examples/msgbox_demo.has
new file mode 100644
index 0000000..66a23eb
--- /dev/null
+++ b/examples/msgbox_demo.has
@@ -0,0 +1,162 @@
+// msgbox_demo.has
+// Demonstrates the GUI widget library: DrawMsgBox with word-wrapped text.
+//
+// Graphics mode: 320x256x32 (mode 0, 5 bitplanes, line-interleaved)
+// Font: lib/font8x8.s  (8x8 pixel characters)
+//
+// Palette indices used:
+//   0  = black       ($000) - screen background
+//   1  = white       ($FFF) - border + text
+//   4  = blue        ($00F) - window background
+//   5  = yellow      ($FF0) - second window border
+//   8  = mid-grey    ($888) - second window background
+//
+// Build (link gui.s, graphics.s, font8x8.s alongside the generated .s):
+//   python -m hasc.cli examples/msgbox_demo.has -o build/msgbox_demo.s
+//   vasmm68k_mot -Fhunkexe -I lib/ -o build/msgbox_demo.o build/msgbox_demo.s lib/gui.s lib/graphics.s lib/font8x8.s lib/helpers.s
+//   vlink -bamigahunk build/msgbox_demo.o -o build/msgbox_demo.exe
+
+#pragma lockreg(a5);
+
+extern var fonts: int;   // font bitmap data from lib/font8x8.s
+
+code main:
+    extern func SetGraphicsMode(mode: int) -> int;
+    extern func ClearScreen() -> int;
+    extern func SetFont(ptr: int) -> int;
+    extern func SetColor(id: int, col: int) -> int;
+    extern func UpdateCopperList() -> int;
+    extern func WaitVBlank() -> int;
+    extern func TakeSystem() -> void;
+    extern func ReleaseSystem() -> void;
+
+    // GUI library functions from lib/gui.s
+    extern func DrawBox(x:int, y:int, w:int, h:int, bg:int, border:int) -> int;
+    extern func DrawMsgBox(x:int, y:int, w:int, h:int, bg:int, border:int, str:int, tc:int) -> int;
+    extern func DrawButton(x:int, y:int, w:int, h:int, bg:int, border:int, str:int, tc:int) -> int;
+    // Mouse event manager (lib/input.s + lib/gui.s)
+    extern func ReadMouse() -> void;
+    extern func GuiPollMouse() -> void;
+    extern func GuiHitTestRect(x:int, y:int, w:int, h:int) -> int;
+    extern func GetGuiMouseX() -> int;
+    extern func GetGuiMouseY() -> int;
+    // Hardware sprite cursor (lib/sprite.s)
+    extern func CreateSprite(idx:int, ptr:int) -> int;
+    extern func ApplySpritePalette(idx:int) -> int;
+    extern func ShowSprite(idx:int) -> int;
+    extern func SetSpritePosition(idx:int, x:int, y:int) -> int;
+
+    public main;
+
+    asm {
+        jsr TakeSystem
+        jsr main
+        jmp ReleaseSystem
+    }
+
+    proc main() -> int {
+        var result: int;
+        var frame: int = 0;
+        var mx: int = 0;
+        var my: int = 0;
+
+        // Initialise 320x256x32 mode
+        result = SetGraphicsMode(0);
+        if (result == -1) {
+            return -1;
+        }
+
+        // Attach the 8x8 bitmap font
+        call SetFont(&fonts);
+
+        // Customise a few palette entries for the demo
+        call SetColor(0, $000);   // 0 = black (background)
+        call SetColor(1, $FFF);   // 1 = white
+        call SetColor(4, $00F);   // 4 = blue  (window fill)
+        call SetColor(5, $FF0);   // 5 = yellow
+        call SetColor(8, $444);   // 8 = dark grey
+
+        call ClearScreen();
+
+        // ---------------------------------------------------------
+        // Sprite cursor: hardware sprite 0 used as mouse pointer
+        // cursor_pal (4 words immediately before cursor) sets color1=$FFF (white)
+        // ---------------------------------------------------------
+        result = CreateSprite(0, &cursor);   // copy fast->chip RAM; store palette
+        call ApplySpritePalette(0);          // write palette into copper list (COLOR17-19)
+        call ShowSprite(0);                  // mark slot visible
+        call SetSpritePosition(0, 160, 128); // initial position: screen centre
+
+        // ---------------------------------------------------------
+        // Window 1: short message - fits on one line
+        // Position (16, 16), size 200x24 pixels
+        // Background: blue (4), border: white (1), text: white (1)
+        // ---------------------------------------------------------
+        result = DrawMsgBox(16, 16, 200, 24, 4, 1, &msg_short, 1);
+
+        // ---------------------------------------------------------
+        // Window 2: long message - wraps across multiple lines
+        // Position (16, 56), size 288x72 pixels  (36 cols x 9 rows)
+        // Background: dark grey (8), border: yellow (5), text: white (1)
+        // ---------------------------------------------------------
+        result = DrawMsgBox(16, 56, 288, 72, 8, 5, &msg_long, 1);
+
+        // ---------------------------------------------------------
+        // Window 3: minimal box with no text - just a filled frame
+        // Position (16, 144), size 64x32
+        // ---------------------------------------------------------
+        result = DrawBox(16, 144, 64, 32, 4, 1);
+
+        // ---------------------------------------------------------
+        // Exit button:
+        // Move the mouse over it and click the left button to exit.
+        // Position (120, 140), size 80x16
+        // ---------------------------------------------------------
+        result = DrawButton(120, 140, 80, 16, 8, 1, &btn_label, 1);
+
+        // ---------------------------------------------------------
+        // Window 4: stress test - word longer than max_cols (hard break)
+        // Position (16, 192), size 96x48 pixels  (12 cols x 6 rows)
+        // ---------------------------------------------------------
+        result = DrawMsgBox(16, 192, 96, 48, 4, 5, &msg_hardwrap, 1);
+
+        // Show the frame
+        call UpdateCopperList();
+
+        // Event loop: hold display until the Exit button is clicked
+        do {
+            call WaitVBlank();
+            call ReadMouse();    // update raw mouse deltas + button state
+            call GuiPollMouse(); // accumulate abs pixel position; detect click edge
+            // Move hardware sprite to follow the mouse cursor
+            mx = GetGuiMouseX();
+            my = GetGuiMouseY();
+            call SetSpritePosition(0, mx, my);
+            if (GuiHitTestRect(100, 132, 120, 24) == 1) {
+                frame = 1;      // Exit button clicked: leave the loop
+            }
+            call UpdateCopperList();
+        } while (frame == 0);
+
+        return 0;
+    }
+
+// String data for the demo windows
+data demo_strings:
+    btn_label.b    = "Exit", 0
+
+    msg_short.b    = "Hello from the HAS GUI library!", 0
+
+    msg_long.b     = "This is a longer message that will not fit on a single line. The word-wrap engine breaks at spaces so no word is split. Rendering stops when the window is full.", 0
+
+    msg_hardwrap.b = "ABCDEFGHIJKLMNOPQRSTUVWXYZ no-space-here forced-break test end.", 0
+
+// Sprite 0 cursor data (classic 11-line arrow, top-left hotspot)
+// Palette word layout (4 words = 8 bytes before cursor label, required by CreateSprite):
+//   color0 = $000 (transparent), color1 = $FFF (white, used for all pixels),
+//   color2 = $CCC (light grey), color3 = $888 (mid grey)
+// Sprite data layout: height, ctrl0, ctrl1, (plane0,plane1) x height, 0,0 terminator
+// All rows use plane0=shape, plane1=$0000 so pixels select color1 (white).
+data cursor_data:
+    cursor_pal.w = $000, $FFF, $CCC, $888
+    cursor.w = 11, 0, 0, $8000, 0, $C000, 0, $E000, 0, $F000, 0, $F800, 0, $FC00, 0, $FE00, 0, $EC00, 0, $C600, 0, $8300, 0, $0300, 0, 0, 0
diff --git a/lib/graphics.s b/lib/graphics.s
index 0f35cf9..8854a32 100644
--- a/lib/graphics.s
+++ b/lib/graphics.s
@@ -37,6 +37,9 @@ GFX_FONT_PLANES      EQU 5                ; Font assets are always expanded to 5
     XDEF SetColor
     XDEF LoadPalette
     XDEF ShowPicture
+    XDEF _DrawChar
+    XDEF gfx_text_cursor_x
+    XDEF gfx_text_cursor_y
 
 ; ---------- Graphics support wrappers ----------
 ; These minimal wrappers map the public names used by generated code
diff --git a/lib/gui.i b/lib/gui.i
new file mode 100644
index 0000000..c2f7709
--- /dev/null
+++ b/lib/gui.i
@@ -0,0 +1,70 @@
+; gui.i - Include file for gui.s
+;
+; Provides:
+;   - GADGET struct field offsets (EQU constants)
+;   - GADGET_TYPE constants
+;   - XREF declarations for all public gui.s entry points
+;
+; Usage in assembly:
+;   include "gui.i"
+;
+; Usage in HAS (declare each needed function with extern func):
+;   extern func FillRect(x:int, y:int, w:int, h:int, color:int) -> int;
+;   ... (see bottom of this file for the full set)
+
+    ifnd GUI_I
+GUI_I = 1
+
+; ============================================================
+; GADGET struct layout (20 bytes)
+; Base address passed to DrawGadget(gadget_ptr).
+; All coordinate / size fields are WORD (sign-extended to LONG by callee).
+; ============================================================
+
+GADGET_X        EQU  0   ; word - screen X position in pixels
+GADGET_Y        EQU  2   ; word - screen Y position in pixels
+GADGET_W        EQU  4   ; word - width in pixels (multiples of 8 recommended)
+GADGET_H        EQU  6   ; word - height in pixels (multiples of 8 recommended)
+GADGET_BG       EQU  8   ; word - background fill palette index (0-31 for mode 0)
+GADGET_BORDER   EQU 10   ; word - border frame palette index (0-31)
+GADGET_TEXT     EQU 12   ; long - pointer to null-terminated message string
+GADGET_TCOLOR   EQU 16   ; word - text palette index (0-31)
+GADGET_TYPE     EQU 18   ; word - gadget type selector (see GADGET_TYPE_* below)
+GADGET_SIZE     EQU 20   ; struct size in bytes (for allocation)
+
+; ============================================================
+; GADGET_TYPE values
+; ============================================================
+
+GADGET_TYPE_MSGBOX  EQU 0   ; message box with word-wrapped text
+GADGET_TYPE_BUTTON  EQU 1   ; clickable button with centred label
+
+; ============================================================
+; External references (assembled in gui.s)
+; ============================================================
+
+    XREF FillRect
+    XREF DrawHLine
+    XREF DrawVLine
+    XREF DrawBox
+    XREF DrawWrappedText
+    XREF DrawMsgBox
+    XREF DrawButton
+    XREF DrawGadget
+    XREF GuiPollMouse
+    XREF GuiHitTest
+    XREF GuiHitTestRect
+
+    endif   ; GUI_I
+
+; ============================================================
+; HAS extern func declarations (copy into your .has file as needed)
+; ============================================================
+;
+;   extern func FillRect(x:int, y:int, w:int, h:int, color:int) -> int;
+;   extern func DrawHLine(x:int, y:int, len:int, color:int) -> int;
+;   extern func DrawVLine(x:int, y:int, len:int, color:int) -> int;
+;   extern func DrawBox(x:int, y:int, w:int, h:int, bg:int, border:int) -> int;
+;   extern func DrawWrappedText(cx:int, cy:int, cols:int, rows:int, str:int, color:int) -> int;
+;   extern func DrawMsgBox(x:int, y:int, w:int, h:int, bg:int, border:int, str:int, tc:int) -> int;
+;   extern func DrawGadget(gadget_ptr:int) -> int;
diff --git a/lib/gui.s b/lib/gui.s
new file mode 100644
index 0000000..8ace336
--- /dev/null
+++ b/lib/gui.s
@@ -0,0 +1,1004 @@
+; gui.s - HAS GUI widget library for Motorola 68000 / Amiga
+;
+; Supports mode 0 (320x256x32, 5 planes, 40 bytes/row) and
+;                 mode 1 (640x256x16, 4 planes, 80 bytes/row); both line-interleaved.
+; Screen memory layout:
+;   mode 0 byte offset for pixel (x,y): y*200 + plane*40 + (x>>3)
+;   mode 1 byte offset for pixel (x,y): y*320 + plane*80 + (x>>3)
+;   bit within byte: (7 - (x & 7))  [bit 7 = leftmost pixel]
+;
+; Calling convention (matches graphics.s):
+;   link a6,#N  with arguments at 8(a6), 12(a6), 16(a6), ...  (longs)
+;   Return value in d0 (0 = success, -1 = error).
+;   Callee saves d1-d7 / a0-a4; d0 is the return register.
+;   a5 is intentionally not saved (used as custom chip base via #pragma lockreg(a5)).
+;   Arguments pushed right-to-left (first arg is at lowest address = 8(a6)).
+;
+; External dependencies (from graphics.s):
+;   gfx_current_screen_ptr  -- long pointer to active screen buffer
+;   gfx_current_mode        -- word: 0=lores, 1=hires, 2=HAM6
+;   _DrawChar               -- draw single char: D0=ASCII, D1=color
+;   gfx_text_cursor_x       -- word: current text column
+;   gfx_text_cursor_y       -- word: current text row
+;
+; Public entry points (all use stack-frame calling convention):
+;   FillRect(x,y,w,h,color)
+;   DrawHLine(x,y,len,color)
+;   DrawVLine(x,y,len,color)
+;   DrawBox(x,y,w,h,bg_color,border_color)
+;   DrawWrappedText(cx,cy,max_cols,max_rows,str_ptr,text_color)
+;   DrawMsgBox(x,y,w,h,bg_color,border_color,str_ptr,text_color)
+;   DrawGadget(gadget_ptr)
+
+
+    include "hardware.i"
+
+    SECTION gui_code,CODE
+
+    XDEF FillRect
+    XDEF DrawHLine
+    XDEF DrawVLine
+    XDEF DrawBox
+    XDEF DrawWrappedText
+    XDEF DrawMsgBox
+    XDEF DrawButton
+    XDEF DrawGadget
+    XDEF GuiPollMouse
+    XDEF GuiHitTest
+    XDEF GuiHitTestRect
+    XDEF GetGuiMouseX
+    XDEF GetGuiMouseY
+
+    XREF gfx_current_screen_ptr
+    XREF gfx_current_mode
+    XREF _DrawChar
+    XREF gfx_text_cursor_x
+    XREF gfx_text_cursor_y
+    XREF GetMouseDX
+    XREF GetMouseDY
+    XREF GetMouseLBtn
+
+
+; ============================================================
+; FillRect(x, y, w, h, color)
+;   8(a6)  = x      - left pixel (long)
+;   12(a6) = y      - top pixel (long)
+;   16(a6) = w      - width in pixels (long)
+;   20(a6) = h      - height in pixels (long)
+;   24(a6) = color  - palette index 0-31 (long)
+;
+; Fills a solid axis-aligned rectangle using the current mode's line-interleaved layout.
+; Reads gfx_current_mode at call time: mode 0 uses 5 planes/40 bytes, mode 1 uses 4 planes/80 bytes.
+; For each bitplane: if (color >> plane) & 1, SET covered bits; otherwise CLEAR them.
+; Handles partial left/right bytes via bit-masks.
+; Returns d0 = 0.
+; ============================================================
+FillRect:
+    link a6,#-8                     ; locals: -1(a6)=lmask, -2(a6)=rmask, -4(a6)=width_bytes, -6(a6)=row_stride, -8(a6)=num_planes
+    movem.l d1-d7/a0-a4,-(sp)
+
+    ; Bail on zero/negative size
+    move.l 16(a6),d0                ; w
+    tst.l d0
+    ble .fr_exit
+    move.l 20(a6),d0                ; h
+    tst.l d0
+    ble .fr_exit
+
+    ; ---- Determine mode-dependent parameters ----
+    move.w gfx_current_mode,d0
+    tst.w d0
+    bne .fr_hires
+    ; Mode 0: 320x256, 5 planes, 40 bytes/row
+    move.w #40,-4(a6)               ; width_bytes
+    move.w #200,-6(a6)              ; row_stride = 5*40
+    move.w #5,-8(a6)                ; num_planes
+    bra .fr_mode_set
+.fr_hires:
+    ; Mode 1: 640x256, 4 planes, 80 bytes/row
+    move.w #80,-4(a6)               ; width_bytes
+    move.w #320,-6(a6)              ; row_stride = 4*80
+    move.w #4,-8(a6)                ; num_planes
+.fr_mode_set:
+
+    ; ---- Precompute left_byte and right_byte (in address registers a2/a3) ----
+    ; left_byte = x >> 3
+    move.l 8(a6),d0
+    lsr.l #3,d0
+    move.l d0,a2                    ; a2 = left_byte
+
+    ; right_byte = (x + w - 1) >> 3
+    move.l 8(a6),d0
+    add.l 16(a6),d0
+    subq.l #1,d0                    ; x1 = x + w - 1
+    lsr.l #3,d0
+    move.l d0,a3                    ; a3 = right_byte
+
+    ; ---- Precompute lmask = gui_lmask[ x & 7 ] ----
+    move.l 8(a6),d0
+    and.l #7,d0
+    lea gui_lmask,a1
+    move.b (a1,d0.w),-1(a6)         ; store lmask byte
+
+    ; ---- Precompute rmask = gui_rmask[ (x+w-1) & 7 ] ----
+    move.l 8(a6),d0
+    add.l 16(a6),d0
+    subq.l #1,d0
+    and.l #7,d0
+    lea gui_rmask,a1
+    move.b (a1,d0.w),-2(a6)         ; store rmask byte
+
+    move.l gfx_current_screen_ptr,a0   ; a0 = screen base (stays constant)
+    move.l 24(a6),d4                   ; d4 = color (constant)
+
+    ; ---- Outer loop: plane 0..4 ----
+    moveq #0,d5                     ; d5 = plane counter
+
+.fr_plane_loop:
+    ; fill_byte: if (color >> plane) & 1 then 0xFF else 0x00
+    move.l d4,d6
+    lsr.l d5,d6                     ; shift color right by plane count
+    and.l #1,d6                     ; isolate LSB
+    neg.l d6                        ; 1 -> 0xFFFFFFFF, 0 -> 0x00000000
+
+    ; Reset row cursor to y for this plane
+    move.l 12(a6),d7                ; d7 = current absolute pixel row (= y)
+    move.l 20(a6),d3
+    subq.l #1,d3                    ; d3 = h-1 (dbra counter)
+
+.fr_row_loop:
+    ; Compute: a1 = screen_base + row*200 + plane*40 + left_byte
+    move.l d7,d0
+    mulu.w -6(a6),d0                ; d0 = row * row_stride
+    move.l d5,d1
+    mulu.w -4(a6),d1                ; d1 = plane * width_bytes
+    add.l d1,d0
+    add.l a2,d0                     ; d0 += left_byte
+    move.l a0,a1
+    add.l d0,a1                     ; a1 = address of first byte for this row/plane
+
+    ; ---- Single-byte span? ----
+    cmpa.l a3,a2                    ; left_byte == right_byte?
+    bne .fr_multi_bytes
+
+    ; Combined mask = lmask & rmask
+    moveq #0,d0
+    move.b -1(a6),d0                ; d0 = lmask
+    moveq #0,d1
+    move.b -2(a6),d1                ; d1 = rmask
+    and.b d1,d0                     ; d0 = combined mask
+    tst.b d6                        ; fill_byte == 0?
+    beq .fr_single_clear
+    ; SET bits under mask
+    move.b (a1),d1
+    or.b d0,d1
+    move.b d1,(a1)
+    bra .fr_row_next
+
+.fr_single_clear:
+    ; CLEAR bits under mask
+    not.b d0                        ; ~combined_mask
+    move.b (a1),d1
+    and.b d0,d1
+    move.b d1,(a1)
+    bra .fr_row_next
+
+    ; ---- Multi-byte span ----
+.fr_multi_bytes:
+    ; Left partial byte: apply lmask
+    moveq #0,d0
+    move.b -1(a6),d0                ; d0 = lmask
+    tst.b d6
+    beq .fr_left_clear
+    move.b (a1),d1
+    or.b d0,d1
+    move.b d1,(a1)+                 ; write and advance
+    bra .fr_mid_bytes
+
+.fr_left_clear:
+    not.b d0                        ; ~lmask
+    move.b (a1),d1
+    and.b d0,d1
+    move.b d1,(a1)+                 ; write and advance
+
+.fr_mid_bytes:
+    ; Middle full bytes: count = right_byte - left_byte - 1
+    move.l a3,d2
+    sub.l a2,d2                     ; d2 = right_byte - left_byte
+    subq.l #1,d2                    ; d2 = middle byte count (may be 0)
+    tst.l d2
+    beq .fr_right_byte              ; 0 middle bytes: go straight to right (invariant: d2>=0)
+    subq.l #1,d2                    ; d2 = dbra count (count-1)
+    tst.b d6
+    beq .fr_mid_clear
+
+.fr_mid_set:
+    move.b #$FF,(a1)+
+    dbra d2,.fr_mid_set
+    bra .fr_right_byte
+
+.fr_mid_clear:
+    clr.b (a1)+
+    dbra d2,.fr_mid_clear
+    ; fall through to right byte
+
+.fr_right_byte:
+    ; Right partial byte: apply rmask
+    moveq #0,d0
+    move.b -2(a6),d0                ; d0 = rmask
+    tst.b d6
+    beq .fr_right_clear
+    move.b (a1),d1
+    or.b d0,d1
+    move.b d1,(a1)
+    bra .fr_row_next
+
+.fr_right_clear:
+    not.b d0                        ; ~rmask
+    move.b (a1),d1
+    and.b d0,d1
+    move.b d1,(a1)
+
+.fr_row_next:
+    addq.l #1,d7                    ; advance to next scanline
+    dbra d3,.fr_row_loop            ; h iterations
+
+    addq.l #1,d5                    ; next plane
+    cmp.w -8(a6),d5
+    blt .fr_plane_loop              ; num_planes iterations
+
+.fr_exit:
+    moveq #0,d0
+    movem.l (sp)+,d1-d7/a0-a4
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawHLine(x, y, len, color)
+;   Draw a horizontal line of 'len' pixels starting at (x,y).
+;   Delegates to FillRect(x, y, len, 1, color).
+; ============================================================
+DrawHLine:
+    link a6,#0
+    move.l 20(a6),-(sp)             ; color  (arg5)
+    move.l #1,-(sp)                 ; h=1    (arg4)
+    move.l 16(a6),-(sp)             ; len=w  (arg3)
+    move.l 12(a6),-(sp)             ; y      (arg2)
+    move.l 8(a6),-(sp)              ; x      (arg1)
+    jsr FillRect
+    lea 20(sp),sp
+    ; d0 = 0 from FillRect
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawVLine(x, y, len, color)
+;   Draw a vertical line of 'len' pixels starting at (x,y).
+;   Delegates to FillRect(x, y, 1, len, color).
+; ============================================================
+DrawVLine:
+    link a6,#0
+    move.l 20(a6),-(sp)             ; color  (arg5)
+    move.l 16(a6),-(sp)             ; len=h  (arg4)
+    move.l #1,-(sp)                 ; w=1    (arg3)
+    move.l 12(a6),-(sp)             ; y      (arg2)
+    move.l 8(a6),-(sp)              ; x      (arg1)
+    jsr FillRect
+    lea 20(sp),sp
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawBox(x, y, w, h, bg_color, border_color)
+;   8(a6)  = x
+;   12(a6) = y
+;   16(a6) = w
+;   20(a6) = h
+;   24(a6) = bg_color     - fill color for interior
+;   28(a6) = border_color - color for 1-pixel border frame
+;
+;   Draws a filled rectangle then a 1-pixel border on all four edges.
+;   Interior (bg) fill is drawn first; border is painted on top.
+;   Left/right edge height = h-2 (spans interior rows only, avoiding
+;   overlap with top/bottom corners which are already filled).
+; ============================================================
+DrawBox:
+    link a6,#0
+    movem.l d1-d5,-(sp)            ; FillRect preserves d1-d7, so these survive calls
+
+    move.l 8(a6),d1                ; d1 = x  (preserved across FillRect calls)
+    move.l 12(a6),d2               ; d2 = y
+    move.l 16(a6),d3               ; d3 = w
+    move.l 20(a6),d4               ; d4 = h
+
+    tst.l d3
+    ble .db_exit
+    tst.l d4
+    ble .db_exit
+
+    ; ---- 1. Background fill: FillRect(x, y, w, h, bg) ----
+    move.l 24(a6),-(sp)
+    move.l d4,-(sp)
+    move.l d3,-(sp)
+    move.l d2,-(sp)
+    move.l d1,-(sp)
+    jsr FillRect
+    lea 20(sp),sp
+    ; d1-d4 preserved by FillRect
+
+    ; ---- 2. Top edge: FillRect(x, y, w, 1, border) ----
+    move.l 28(a6),-(sp)
+    move.l #1,-(sp)
+    move.l d3,-(sp)
+    move.l d2,-(sp)
+    move.l d1,-(sp)
+    jsr FillRect
+    lea 20(sp),sp
+
+    ; ---- 3. Bottom edge: FillRect(x, y+h-1, w, 1, border) ----
+    move.l d4,d5
+    add.l d2,d5
+    subq.l #1,d5                    ; d5 = y + h - 1
+    move.l 28(a6),-(sp)
+    move.l #1,-(sp)
+    move.l d3,-(sp)
+    move.l d5,-(sp)                 ; y+h-1
+    move.l d1,-(sp)
+    jsr FillRect
+    lea 20(sp),sp
+
+    ; ---- 4 & 5: Left/right edges (only when h > 2) ----
+    move.l d4,d5
+    subq.l #2,d5                    ; d5 = h - 2 (interior edge height)
+    tst.l d5
+    ble .db_exit
+
+    ; 4. Left edge: FillRect(x, y+1, 1, h-2, border)
+    move.l 28(a6),-(sp)
+    move.l d5,-(sp)                 ; h-2
+    move.l #1,-(sp)                 ; w=1
+    move.l 12(a6),d0
+    addq.l #1,d0                    ; d0 = y+1
+    move.l d0,-(sp)
+    move.l d1,-(sp)                 ; x
+    jsr FillRect
+    lea 20(sp),sp
+    ; d5 = h-2 preserved (FillRect preserves d5)
+
+    ; 5. Right edge: FillRect(x+w-1, y+1, 1, h-2, border)
+    move.l 28(a6),-(sp)
+    move.l d5,-(sp)                 ; h-2
+    move.l #1,-(sp)                 ; w=1
+    move.l 12(a6),d0
+    addq.l #1,d0                    ; y+1
+    move.l d0,-(sp)
+    move.l d1,d0
+    add.l d3,d0
+    subq.l #1,d0                    ; x+w-1
+    move.l d0,-(sp)
+    jsr FillRect
+    lea 20(sp),sp
+
+.db_exit:
+    moveq #0,d0
+    movem.l (sp)+,d1-d5
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawWrappedText(cx, cy, max_cols, max_rows, str_ptr, text_color)
+;   8(a6)  = cx         - starting character column (0-based, char units)
+;   12(a6) = cy         - starting character row (0-based, char units)
+;   16(a6) = max_cols   - maximum characters per line (> 0)
+;   20(a6) = max_rows   - maximum number of lines to render (> 0)
+;   24(a6) = str_ptr    - pointer to null-terminated ASCII string
+;   28(a6) = text_color - palette index for text (0-31)
+;
+;   Word-wraps the string to fit within (max_cols x max_rows) character cells.
+;   Break points: last whitespace (ASCII 0x20) before the column limit.
+;   If no space is found, a hard break is applied at max_cols.
+;   Rendering stops when max_rows is exhausted or the string ends.
+;
+;   Register map (all saved on entry/exit):
+;     a0 = cur_ptr  (advances through string)
+;     a1 = scan ptr (inner scan loop)
+;     a2 = last_space_ptr (0 = none found this line)
+;     a3 = end_ptr  (exclusive end of segment to print)
+;     a4 = next_ptr (cur_ptr for next row)
+;     d2 = col cursor (cx + chars drawn on current line)
+;     d3 = row cursor (cy + row_index, absolute)
+;     d4 = max_cols (constant)
+;     d5 = rows_left
+;     d6 = text_color (constant)
+;     d7 = scan column counter
+; ============================================================
+DrawWrappedText:
+    link a6,#0
+    movem.l d1-d7/a0-a4,-(sp)
+
+    move.l 20(a6),d5               ; d5 = rows_left
+    tst.l d5
+    ble .dwt_exit
+
+    move.l 16(a6),d4               ; d4 = max_cols
+    tst.l d4
+    ble .dwt_exit
+
+    move.l 28(a6),d6               ; d6 = text_color
+    move.l 12(a6),d3               ; d3 = row cursor (abs char row = cy initially)
+    move.l 24(a6),a0               ; a0 = cur_ptr
+
+.dwt_row_loop:
+    ; Scan up to max_cols characters looking for last space / NUL
+    move.l a0,a1                   ; a1 = scan pointer
+    suba.l a2,a2                   ; a2 = last_space_ptr = NULL (0)
+    move.l d4,d7                   ; d7 = cols_remaining
+
+.dwt_scan:
+    tst.l d7
+    beq .dwt_hit_limit             ; scanned max_cols chars
+    moveq #0,d0
+    move.b (a1),d0
+    tst.b d0
+    beq .dwt_hit_nul               ; NUL found
+    cmp.b #$20,d0                  ; space?
+    bne .dwt_no_space
+    move.l a1,a2                   ; record last space position
+.dwt_no_space:
+    addq.l #1,a1
+    subq.l #1,d7
+    bra .dwt_scan
+
+.dwt_hit_nul:
+    ; NUL within max_cols: print a0..a1 (a1 = NUL byte), then done
+    move.l a1,a3                   ; a3 = end_ptr (exclusive: NUL pos)
+    move.l a1,a4                   ; a4 = next_ptr (points to NUL → exits after)
+    bra .dwt_print
+
+.dwt_hit_limit:
+    ; Reached max_cols. Break at last space if available.
+    move.l a2,d0
+    tst.l d0
+    beq .dwt_hard_break            ; no space found
+
+    ; Soft break: print up to (not including) the space
+    move.l a2,a3                   ; a3 = end_ptr = space position (exclusive)
+    move.l a2,a4
+    addq.l #1,a4                   ; a4 = next_ptr = past space
+    bra .dwt_print
+
+.dwt_hard_break:
+    ; No space within max_cols: break at the column limit
+    move.l a1,a3                   ; a3 = end_ptr = a0 + max_cols
+    move.l a1,a4                   ; a4 = next_ptr = same (continue from break)
+
+.dwt_print:
+    ; Print chars from a0 to a3 (exclusive) at character position (cx, d3)
+    move.l 8(a6),d2                ; d2 = column cursor = cx
+
+.dwt_char:
+    cmpa.l a3,a0                   ; a0 >= end_ptr?
+    bge .dwt_line_done
+
+    ; Set cursor and draw one character
+    move.w d2,gfx_text_cursor_x    ; column (low word of d2)
+    move.w d3,gfx_text_cursor_y    ; row    (low word of d3)
+    moveq #0,d0
+    move.b (a0)+,d0                ; d0 = ASCII char; advance cur_ptr
+    move.l d6,d1                   ; d1 = color
+    jsr _DrawChar                  ; draw at cursor; preserves d1-d7,a0-a4
+    addq.l #1,d2                   ; advance column cursor
+    bra .dwt_char
+
+.dwt_line_done:
+    ; Advance cur_ptr to next_ptr
+    move.l a4,a0
+    ; If cur_ptr now points to NUL (string done), exit
+    tst.b (a0)
+    beq .dwt_exit
+
+    ; Move to next row
+    addq.l #1,d3                   ; row_cursor++
+    subq.l #1,d5                   ; rows_left--
+    tst.l d5
+    bgt .dwt_row_loop
+
+.dwt_exit:
+    moveq #0,d0
+    movem.l (sp)+,d1-d7/a0-a4
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawMsgBox(x, y, w, h, bg_color, border_color, str_ptr, text_color)
+;   8(a6)  = x
+;   12(a6) = y
+;   16(a6) = w            - width in pixels (should be multiple of 8)
+;   20(a6) = h            - height in pixels (should be multiple of 8)
+;   24(a6) = bg_color     - window background palette index
+;   28(a6) = border_color - frame palette index
+;   32(a6) = str_ptr      - pointer to null-terminated message string
+;   36(a6) = text_color   - text palette index
+;
+;   Draws a bordered window and renders word-wrapped text inside it.
+;   Interior text area has 1-character padding on all sides.
+;   Text units: 1 character = 8 pixels (8x8 font).
+; ============================================================
+DrawMsgBox:
+    link a6,#0
+    movem.l d1-d4,-(sp)            ; d1-d4 survive nested calls (FillRect/DrawBox preserve them)
+
+    ; ---- Draw the window frame ----
+    move.l 28(a6),-(sp)            ; border_color (arg6)
+    move.l 24(a6),-(sp)            ; bg_color     (arg5)
+    move.l 20(a6),-(sp)            ; h            (arg4)
+    move.l 16(a6),-(sp)            ; w            (arg3)
+    move.l 12(a6),-(sp)            ; y            (arg2)
+    move.l 8(a6),-(sp)             ; x            (arg1)
+    jsr DrawBox
+    lea 24(sp),sp
+
+    ; ---- Compute text area in character units ----
+    ; cx = x/8 + 1  (1-char padding from left border)
+    move.l 8(a6),d1
+    lsr.l #3,d1
+    addq.l #1,d1                   ; d1 = cx
+
+    ; cy = y/8 + 1
+    move.l 12(a6),d2
+    lsr.l #3,d2
+    addq.l #1,d2                   ; d2 = cy
+
+    ; max_cols = w/8 - 2  (subtract left+right 1-char padding)
+    move.l 16(a6),d3
+    lsr.l #3,d3
+    subq.l #2,d3                   ; d3 = max_cols
+
+    ; max_rows = h/8 - 2
+    move.l 20(a6),d4
+    lsr.l #3,d4
+    subq.l #2,d4                   ; d4 = max_rows
+
+    ; Bail if text area is too small
+    tst.l d3
+    ble .dmb_exit
+    tst.l d4
+    ble .dmb_exit
+
+    ; ---- Render word-wrapped text ----
+    ; DrawWrappedText(cx, cy, max_cols, max_rows, str_ptr, text_color)
+    move.l 36(a6),-(sp)            ; text_color (arg6)
+    move.l 32(a6),-(sp)            ; str_ptr    (arg5)
+    move.l d4,-(sp)                ; max_rows   (arg4)
+    move.l d3,-(sp)                ; max_cols   (arg3)
+    move.l d2,-(sp)                ; cy         (arg2)
+    move.l d1,-(sp)                ; cx         (arg1)
+    jsr DrawWrappedText
+    lea 24(sp),sp
+
+.dmb_exit:
+    moveq #0,d0
+    movem.l (sp)+,d1-d4
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawGadget(gadget_ptr)
+;   8(a6) = gadget_ptr - pointer to a GADGET struct (see gui.i for layout)
+;
+;   Dispatches to the appropriate renderer based on GADGET_TYPE field.
+;   Type 0 = message box (DrawMsgBox), type 1 = button (DrawButton).
+;   Unknown types are silently ignored (returns 0).
+; ============================================================
+DrawGadget:
+    link a6,#0
+    movem.l d1/a0,-(sp)
+
+    move.l 8(a6),a0                ; a0 = gadget struct pointer
+
+    ; Dispatch on GADGET_TYPE: 0=msgbox, 1=button; skip unknown
+    move.w 18(a0),d1               ; 18 = GADGET_TYPE offset
+    tst.w d1
+    beq .dg_dispatch               ; type 0: msgbox
+    cmp.w #1,d1
+    bne .dg_done                   ; unknown type: skip
+
+.dg_dispatch:
+    ; Push all 8 args (identical layout for DrawMsgBox and DrawButton)
+    moveq #0,d1
+    move.w 16(a0),d1               ; GADGET_TCOLOR (unsigned)
+    move.l d1,-(sp)                ; arg8 = text_color
+
+    move.l 12(a0),-(sp)            ; GADGET_TEXT  arg7 = str_ptr (long)
+
+    moveq #0,d1
+    move.w 10(a0),d1               ; GADGET_BORDER (unsigned)
+    move.l d1,-(sp)                ; arg6 = border_color
+
+    moveq #0,d1
+    move.w 8(a0),d1                ; GADGET_BG (unsigned)
+    move.l d1,-(sp)                ; arg5 = bg_color
+
+    moveq #0,d1
+    move.w 6(a0),d1                ; GADGET_H (unsigned, positive pixels)
+    move.l d1,-(sp)                ; arg4 = h
+
+    moveq #0,d1
+    move.w 4(a0),d1                ; GADGET_W (unsigned, positive pixels)
+    move.l d1,-(sp)                ; arg3 = w
+
+    move.w 2(a0),d1                ; GADGET_Y (signed coordinate)
+    ext.l d1                       ; sign-extend: allows negative y
+    move.l d1,-(sp)                ; arg2 = y
+
+    move.w 0(a0),d1                ; GADGET_X (signed coordinate)
+    ext.l d1                       ; sign-extend: allows negative x
+    move.l d1,-(sp)                ; arg1 = x
+
+    ; Call correct renderer (a0 still valid above pushed args)
+    tst.w 18(a0)
+    bne .dg_call_button
+    jsr DrawMsgBox
+    bra .dg_pop
+.dg_call_button:
+    jsr DrawButton
+.dg_pop:
+    lea 32(sp),sp
+
+.dg_done:
+    moveq #0,d0
+    movem.l (sp)+,d1/a0
+    unlk a6
+    rts
+
+
+; ============================================================
+; DrawButton(x, y, w, h, bg, border, label, tcolor)
+;   8(a6)  = x      - left pixel
+;   12(a6) = y      - top pixel
+;   16(a6) = w      - width in pixels (multiple of 8 recommended)
+;   20(a6) = h      - height in pixels (multiple of 8 recommended)
+;   24(a6) = bg     - background palette index
+;   28(a6) = border - border palette index
+;   32(a6) = label  - pointer to null-terminated label string
+;   36(a6) = tcolor - text palette index
+;
+;   Draws a bordered box with the label centered horizontally and
+;   vertically (snapped to the 8-pixel character grid).
+;   Returns d0 = 0.
+; ============================================================
+DrawButton:
+    link a6,#-4                     ; -4(a6) = strlen local (long)
+    movem.l d1-d5/a0,-(sp)
+
+    ; ---- 1. Background fill ----
+    move.l 24(a6),-(sp)             ; bg
+    move.l 20(a6),-(sp)             ; h
+    move.l 16(a6),-(sp)             ; w
+    move.l 12(a6),-(sp)             ; y
+    move.l 8(a6),-(sp)              ; x
+    jsr FillRect
+    lea 20(sp),sp
+
+    ; ---- 2. Top highlight (1 px, border color = bright) ----
+    move.l 28(a6),-(sp)             ; color = border (highlight)
+    move.l 16(a6),-(sp)             ; w
+    move.l 12(a6),-(sp)             ; y (top edge)
+    move.l 8(a6),-(sp)              ; x
+    jsr DrawHLine
+    lea 16(sp),sp
+
+    ; ---- 3. Left highlight (1 px, border color = bright) ----
+    move.l 28(a6),-(sp)             ; color = border (highlight)
+    move.l 20(a6),-(sp)             ; h
+    move.l 12(a6),-(sp)             ; y
+    move.l 8(a6),-(sp)              ; x
+    jsr DrawVLine
+    lea 16(sp),sp
+
+    ; ---- 4. Bottom shadow (1 px, black = color 0) ----
+    move.l #0,-(sp)                 ; color = 0 (shadow)
+    move.l 16(a6),-(sp)             ; w
+    move.l 20(a6),d1
+    add.l 12(a6),d1
+    subq.l #1,d1                    ; d1 = y + h - 1
+    move.l d1,-(sp)                 ; y = bottom edge
+    move.l 8(a6),-(sp)              ; x
+    jsr DrawHLine
+    lea 16(sp),sp
+
+    ; ---- 5. Right shadow (1 px, black = color 0) ----
+    move.l #0,-(sp)                 ; color = 0 (shadow)
+    move.l 20(a6),-(sp)             ; h
+    move.l 12(a6),-(sp)             ; y
+    move.l 16(a6),d1
+    add.l 8(a6),d1
+    subq.l #1,d1                    ; d1 = x + w - 1
+    move.l d1,-(sp)                 ; x = right edge
+    jsr DrawVLine
+    lea 16(sp),sp
+
+    ; ---- 6. Measure label (strlen) ----
+    move.l 32(a6),a0                ; label ptr
+    clr.l -4(a6)                    ; len = 0
+.dbt_len:
+    tst.b (a0)+
+    beq .dbt_len_done
+    addq.l #1,-4(a6)
+    bra .dbt_len
+.dbt_len_done:
+    tst.l -4(a6)
+    beq .dbt_done                   ; empty label: skip rendering
+
+    ; ---- 7. Horizontal centering ----
+    ;    cx = (x + (w - len*8) / 2) / 8
+    move.l -4(a6),d1                ; len
+    lsl.l #3,d1                     ; len * 8  (pixel width of label)
+    move.l 16(a6),d2                ; w
+    sub.l d1,d2                     ; d2 = w - label_px
+    tst.l d2
+    bge .dbt_hpad_ok
+    clr.l d2                        ; clamp: label wider than button
+.dbt_hpad_ok:
+    lsr.l #1,d2                     ; d2 = (w - label_px) / 2
+    add.l 8(a6),d2                  ; d2 = x + hpad_px
+    lsr.l #3,d2                     ; d2 = cx  (snap to char grid)
+    move.l d2,d1                    ; d1 = cx
+
+    ; ---- 8. Vertical centering ----
+    ;    cy = (y + h/2) / 8   - rounds text row to nearest char row
+    move.l 20(a6),d2                ; h
+    lsr.l #1,d2                     ; h/2
+    add.l 12(a6),d2                 ; y + h/2
+    lsr.l #3,d2                     ; d2 = cy  (char row)
+
+    ; ---- 9. Render label one char at a time ----
+    move.w d1,gfx_text_cursor_x
+    move.w d2,gfx_text_cursor_y
+    move.l 32(a6),a0                ; reset to label start
+    move.l 36(a6),d5                ; d5 = tcolor (constant)
+.dbt_draw:
+    moveq #0,d0
+    move.b (a0)+,d0                 ; d0 = next ASCII char; NUL = stop
+    tst.b d0
+    beq .dbt_done
+    move.l d5,d1                    ; d1 = color (_DrawChar: D0=char, D1=color)
+    jsr _DrawChar
+    move.w gfx_text_cursor_x,d4
+    addq.w #1,d4
+    move.w d4,gfx_text_cursor_x
+    bra .dbt_draw
+
+.dbt_done:
+    moveq #0,d0
+    movem.l (sp)+,d1-d5/a0
+    unlk a6
+    rts
+
+
+; ============================================================
+; GuiPollMouse()
+;   Must be called once per frame AFTER ReadMouse().
+;   Reads delta movement via GetMouseDX/GetMouseDY and accumulates
+;   into gui_abs_mouse_x/y (x clamped to screen width, y clamped
+;   to 0..255).  Reads button via GetMouseLBtn and writes the
+;   leading-edge (0->1 transition) result into gui_lbtn_edge.
+;   Returns d0 = 0.
+; ============================================================
+GuiPollMouse:
+    link a6,#0
+    movem.l d1-d2,-(sp)
+
+    ; ---- Accumulate X ----
+    jsr GetMouseDX              ; d0 = dx (signed long)
+    move.w gui_abs_mouse_x,d1
+    ext.l d1                    ; d1 = current abs_x
+    add.l d0,d1                 ; d1 = new abs_x
+    tst.l d1
+    bge .gpm_x_pos
+    moveq #0,d1                 ; underflow: clamp to 0
+    bra .gpm_x_done
+.gpm_x_pos:
+    move.w gfx_current_mode,d2
+    tst.w d2
+    bne .gpm_x_hires
+    cmp.l #319,d1               ; mode 0: max x = 319
+    ble .gpm_x_done
+    move.l #319,d1
+    bra .gpm_x_done
+.gpm_x_hires:
+    cmp.l #639,d1               ; mode 1: max x = 639
+    ble .gpm_x_done
+    move.l #639,d1
+.gpm_x_done:
+    move.w d1,gui_abs_mouse_x
+
+    ; ---- Accumulate Y ----
+    jsr GetMouseDY              ; d0 = dy (signed long)
+    move.w gui_abs_mouse_y,d1
+    ext.l d1
+    add.l d0,d1
+    tst.l d1
+    bge .gpm_y_pos
+    moveq #0,d1
+    bra .gpm_y_done
+.gpm_y_pos:
+    cmp.l #255,d1
+    ble .gpm_y_done
+    move.l #255,d1
+.gpm_y_done:
+    move.w d1,gui_abs_mouse_y
+
+    ; ---- Left-button edge detect ----
+    jsr GetMouseLBtn            ; d0 = current lbtn (0 or 1, long)
+    move.w d0,d2                ; d2 = current state
+    moveq #0,d0                 ; d0 = edge = 0 (default: no new click)
+    cmp.w #1,d2
+    bne .gpm_no_edge            ; not pressed: no edge
+    tst.w gui_lbtn_prev
+    bne .gpm_no_edge            ; was held last frame: edge already consumed
+    moveq #1,d0                 ; 0->1 transition: click!
+.gpm_no_edge:
+    move.w d0,gui_lbtn_edge
+    move.w d2,gui_lbtn_prev     ; save current state for next frame
+
+    moveq #0,d0
+    movem.l (sp)+,d1-d2
+    unlk a6
+    rts
+
+
+; ============================================================
+; GuiHitTest(gadget_ptr) -> int
+;   8(a6) = gadget_ptr - pointer to GADGET struct
+;   Returns 1 if gui_lbtn_edge is set AND the absolute mouse
+;   position falls inside [gx..gx+gw) x [gy..gy+gh).
+;   Returns 0 otherwise.  Works for any gadget type.
+; ============================================================
+GuiHitTest:
+    link a6,#0
+    movem.l d1-d5/a0,-(sp)
+
+    tst.w gui_lbtn_edge
+    beq .ght_miss
+
+    move.l 8(a6),a0             ; gadget_ptr
+    move.w 0(a0),d1             ; GADGET_X (signed)
+    ext.l d1
+    move.w 2(a0),d2             ; GADGET_Y (signed)
+    ext.l d2
+    moveq #0,d3
+    move.w 4(a0),d3             ; GADGET_W (unsigned)
+    moveq #0,d4
+    move.w 6(a0),d4             ; GADGET_H (unsigned)
+
+    move.w gui_abs_mouse_x,d5
+    ext.l d5                    ; mx
+    cmp.l d1,d5                 ; mx < gx?
+    blt .ght_miss
+    move.l d1,d0
+    add.l d3,d0                 ; d0 = gx + gw
+    cmp.l d0,d5                 ; mx >= gx+gw?
+    bge .ght_miss
+
+    move.w gui_abs_mouse_y,d5
+    ext.l d5                    ; my
+    cmp.l d2,d5                 ; my < gy?
+    blt .ght_miss
+    move.l d2,d0
+    add.l d4,d0                 ; d0 = gy + gh
+    cmp.l d0,d5                 ; my >= gy+gh?
+    bge .ght_miss
+
+    moveq #1,d0
+    movem.l (sp)+,d1-d5/a0
+    unlk a6
+    rts
+.ght_miss:
+    moveq #0,d0
+    movem.l (sp)+,d1-d5/a0
+    unlk a6
+    rts
+
+
+; ============================================================
+; GuiHitTestRect(x, y, w, h) -> int
+;   8(a6)=x, 12(a6)=y, 16(a6)=w, 20(a6)=h  (all longs, pixels)
+;   Returns 1 if gui_lbtn_edge AND abs mouse in [x..x+w)x[y..y+h).
+;   Convenience alternative to GuiHitTest for HAS callers that
+;   use DrawButton directly without a GADGET struct.
+; ============================================================
+GuiHitTestRect:
+    link a6,#0
+    movem.l d1-d5,-(sp)
+
+    tst.w gui_lbtn_edge
+    beq .ghr_miss
+
+    move.l 8(a6),d1             ; x
+    move.l 12(a6),d2            ; y
+    move.l 16(a6),d3            ; w
+    move.l 20(a6),d4            ; h
+
+    move.w gui_abs_mouse_x,d5
+    ext.l d5                    ; mx
+    cmp.l d1,d5
+    blt .ghr_miss
+    move.l d1,d0
+    add.l d3,d0
+    cmp.l d0,d5
+    bge .ghr_miss
+
+    move.w gui_abs_mouse_y,d5
+    ext.l d5                    ; my
+    cmp.l d2,d5
+    blt .ghr_miss
+    move.l d2,d0
+    add.l d4,d0
+    cmp.l d0,d5
+    bge .ghr_miss
+
+    moveq #1,d0
+    movem.l (sp)+,d1-d5
+    unlk a6
+    rts
+.ghr_miss:
+    moveq #0,d0
+    movem.l (sp)+,d1-d5
+    unlk a6
+    rts
+
+
+; ============================================================
+; GetGuiMouseX() -> int
+;   Returns gui_abs_mouse_x (accumulated clamped X pixel) as a signed long.
+;   No stack frame needed - no arguments.
+; ============================================================
+GetGuiMouseX:
+    move.w gui_abs_mouse_x,d0
+    ext.l d0
+    rts
+
+; ============================================================
+; GetGuiMouseY() -> int
+;   Returns gui_abs_mouse_y (accumulated clamped Y pixel) as a signed long.
+;   No stack frame needed - no arguments.
+; ============================================================
+GetGuiMouseY:
+    move.w gui_abs_mouse_y,d0
+    ext.l d0
+    rts
+
+
+; ============================================================
+; Bit-mask lookup tables (read-only, pc-relative accessible)
+;
+; gui_lmask[i] = 0xFF >> i
+;   Pixels from bit-position i to 7 within a byte (right side of byte).
+;   Used for the leftmost (partial) byte of a filled span.
+;
+; gui_rmask[i] = top (i+1) bits of a byte
+;   Pixels from bit-position 0 to i within a byte (left side of byte).
+;   Used for the rightmost (partial) byte of a filled span.
+;
+; Amiga bit numbering: bit 7 = leftmost pixel, bit 0 = rightmost pixel.
+; ============================================================
+    SECTION gui_data,DATA
+
+gui_lmask:
+    dc.b $FF,$7F,$3F,$1F,$0F,$07,$03,$01
+
+gui_rmask:
+    dc.b $80,$C0,$E0,$F0,$F8,$FC,$FE,$FF
+
+; Mouse event state (updated by GuiPollMouse each frame)
+gui_abs_mouse_x: dc.w 0   ; accumulated absolute X pixel (clamped to screen width-1)
+gui_abs_mouse_y: dc.w 0   ; accumulated absolute Y pixel (clamped to 0..255)
+gui_lbtn_prev:   dc.w 0   ; left-button state from previous GuiPollMouse call
+gui_lbtn_edge:   dc.w 0   ; 1 on the frame the left button is first pressed, else 0
diff --git a/scripts/build_msgbox_demo.sh b/scripts/build_msgbox_demo.sh
new file mode 100755
index 0000000..643b104
--- /dev/null
+++ b/scripts/build_msgbox_demo.sh
@@ -0,0 +1,99 @@
+#!/usr/bin/env bash
+# build_msgbox_demo.sh
+# Compile examples/msgbox_demo.has through the full pipeline:
+#   HAS → .s → vasm per-object → vlink → build/msgbox_demo.exe
+#
+# Usage:
+#   ./scripts/build_msgbox_demo.sh          # from project root
+#
+# Requirements:
+#   - Python venv activated (or python/hasc on PATH)
+#   - vasmm68k_mot on PATH, or set VASM env variable
+#   - vlink on PATH
+
+set -euo pipefail
+
+# ---------------------------------------------------------------------------
+# Paths
+# ---------------------------------------------------------------------------
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+BUILD="$ROOT/build"
+LIB="$ROOT/lib"
+SRC="$ROOT/examples/msgbox_demo.has"
+
+# ---------------------------------------------------------------------------
+# Tool detection
+# ---------------------------------------------------------------------------
+# Allow override: VASM=/path/to/vasmm68k_mot ./scripts/build_msgbox_demo.sh
+VASM="${VASM:-vasmm68k_mot}"
+
+if ! command -v "$VASM" &>/dev/null; then
+    # Fall back to the bundled vasm from the Amiga Assembly VS Code extension
+    BUNDLED="$HOME/.vscode/extensions/prb28.amiga-assembly-1.8.13/resources/bin/linux/vasmm68k_mot"
+    if [[ -x "$BUNDLED" ]]; then
+        VASM="$BUNDLED"
+    else
+        echo "ERROR: vasmm68k_mot not found. Set VASM=/path/to/vasmm68k_mot." >&2
+        exit 1
+    fi
+fi
+
+if ! command -v vlink &>/dev/null; then
+    echo "ERROR: vlink not found. Install vlink and add it to PATH." >&2
+    exit 1
+fi
+
+VASM_FLAGS=(-Fhunk -devpac -I "$LIB")
+
+mkdir -p "$BUILD"
+
+echo "=== Build: msgbox_demo ==="
+echo "  Root : $ROOT"
+echo "  VASM : $VASM"
+echo ""
+
+# ---------------------------------------------------------------------------
+# Step 1: HAS → assembly
+# ---------------------------------------------------------------------------
+echo "[1/3] Compiling HAS source..."
+(cd "$ROOT" && python -m hasc.cli "$SRC" -o "$BUILD/msgbox_demo.s")
+echo "      -> build/msgbox_demo.s"
+
+# ---------------------------------------------------------------------------
+# Step 2: Assemble every object
+# ---------------------------------------------------------------------------
+echo "[2/3] Assembling objects..."
+
+assemble() {
+    local src="$1" obj="$2"
+    echo "      $src -> $(basename "$obj")"
+    "$VASM" "${VASM_FLAGS[@]}" "$src" -o "$obj"
+}
+
+assemble "$BUILD/msgbox_demo.s"   "$BUILD/msgbox_demo.o"
+assemble "$LIB/gui.s"             "$BUILD/gui.o"
+assemble "$LIB/graphics.s"        "$BUILD/graphics.o"
+assemble "$LIB/sprite.s"          "$BUILD/sprite.o"
+assemble "$LIB/font8x8.s"         "$BUILD/font8x8.o"
+assemble "$LIB/helpers.s"         "$BUILD/helpers.o"
+assemble "$LIB/takeover.s"        "$BUILD/takeover.o"
+assemble "$LIB/input.s"           "$BUILD/input.o"
+
+# ---------------------------------------------------------------------------
+# Step 3: Link
+# ---------------------------------------------------------------------------
+echo "[3/3] Linking..."
+vlink -bamigahunk \
+    "$BUILD/msgbox_demo.o" \
+    "$BUILD/gui.o"         \
+    "$BUILD/graphics.o"    \
+    "$BUILD/sprite.o"      \
+    "$BUILD/font8x8.o"     \
+    "$BUILD/helpers.o"     \
+    "$BUILD/takeover.o"    \
+    "$BUILD/input.o"       \
+    -o "$BUILD/msgbox_demo.exe"
+
+echo ""
+echo "=== Done: build/msgbox_demo.exe ==="