Enable absolute mouse (todo: add flag to turn it off)

&& fix(?) a crash if mouse events were delivered too early

Makefile

@@ -27,6 +27,7 @@
 
 DEBUG ?= 0
 MEMSIZE ?= 128
+ENABLE_AUDIO ?= 1
 
 SOURCES = $(wildcard src/*.c)
 
@@ -54,9 +55,12 @@ endif
 # Basic support for changing screen res (with the MacPlusV3 ROM)
 DISP_WIDTH ?= 512
 DISP_HEIGHT ?= 342
-CFLAGS_CFG = -DDISP_WIDTH=$(DISP_WIDTH) -DDISP_HEIGHT=$(DISP_HEIGHT)
+CFLAGS_CFG = -DDISP_WIDTH=$(DISP_WIDTH) -DDISP_HEIGHT=$(DISP_HEIGHT) -DENABLE_AUDIO=$(ENABLE_AUDIO)
 
-all:	main
+all:	main patcher
+
+patcher: src/rom.c
+	$(CC) $(CFLAGS) -DUMAC_STANDALONE_PATCHER -o $@ $<
 
 $(MUSASHI_SRC): $(MUSASHI)/m68kops.h
 
@@ -74,7 +78,7 @@ main:	$(OBJS)
 
 clean:
 	make -C $(MUSASHI) clean
-	rm -f $(MY_OBJS) main
+	rm -f $(MY_OBJS) main patcher
 
 ################################################################################
 # Mac driver sources (no need to generally rebuild

include/machw.h

@@ -81,6 +81,8 @@ extern int overlay;
  * But, that should never happen post-boot.
  */
 #define CLAMP_RAM_ADDR(x) ((x) >= RAM_SIZE ? (x) % RAM_SIZE : (x))
+/* Is the address (previously clamped with CLAMP_RAM_ADDR) the audio trap address? (last byte of audio data) */
+#define IS_RAM_AUDIO_TRAP(x) (x == umac_get_audio_offset() + 2 * 369)
 
 #define IS_VIA(x)       ((ADR24(x) & 0xe80000) == 0xe80000)
 #define IS_IWM(x)       ((ADR24(x) >= 0xdfe1ff) && (ADR24(x) < (0xdfe1ff + 0x2000)))

include/scc.h

@@ -35,6 +35,8 @@ void    scc_write(unsigned int address, uint8_t data);
 uint8_t scc_read(unsigned int address);
 /* Set a new state for the DCD pins: */
 void    scc_set_dcd(int a, int b);
+/* check if scc master interrupt is enabled */
+int scc_get_mie();
 
 #endif
 

include/umac.h

@@ -34,6 +34,7 @@ int     umac_loop(void);
 void    umac_reset(void);
 void    umac_opt_disassemble(int enable);
 void    umac_mouse(int deltax, int deltay, int button);
+void    umac_absmouse(int x, int y, int button);
 void    umac_kbd_event(uint8_t scancode, int down);
 
 static inline void      umac_vsync_event(void)
@@ -53,4 +54,15 @@ static inline unsigned int      umac_get_fb_offset(void)
         return RAM_SIZE - ((DISP_WIDTH * DISP_HEIGHT / 8) + 0x380);
 }
 
+#if ENABLE_AUDIO
+#define umac_get_audio_offset() (RAM_SIZE - 768)
+#define umac_get_audio_offset_end() (RAM_SIZE - 768 + 2 * 370)
+extern unsigned first_audio_sample;
+#define umac_get_first_audio_sample() (first_audio_sample)
+#define umac_reset_first_audio_sample() (first_audio_sample = 0, (void)0)
+
+void umac_audio_trap();
+void umac_audio_cfg(int volume, int sndres);
+#endif
+
 #endif

include/via.h

@@ -40,7 +40,8 @@ struct via_cb {
 void    via_init(struct via_cb *cb);
 void    via_write(unsigned int address, uint8_t data);
 uint8_t via_read(unsigned int address);
-void    via_tick(uint64_t time);
+void    via_tick(int cycles);
+int     via_limit_cycles(int cycles);
 /* Trigger an event on CA1 or CA2: */
 void    via_caX_event(int ca);
 void    via_sr_rx(uint8_t val);

src/main.c

@@ -40,6 +40,7 @@
 #include <errno.h>
 #include <setjmp.h>
 
+#include "umac.h"
 #include "machw.h"
 #include "m68k.h"
 #include "via.h"
@@ -70,8 +71,11 @@ static unsigned int g_int_controller_highest_int = 0;  /* Highest pending interr
 uint8_t *_ram_base;
 uint8_t *_rom_base;
 
+#if ENABLE_AUDIO
+static int umac_volume, umac_sndres;
+#endif
 int overlay = 1;
-static uint64_t global_time_us = 0;
+static uint64_t global_time_us = 0, global_cycles = 0;
 static int sim_done = 0;
 static jmp_buf main_loop_jb;
 
@@ -154,8 +158,14 @@ static void     via_ra_changed(uint8_t val)
                 MDBG("OVERLAY CHANGING\n");
                 update_overlay_layout();
         }
-
+#if ENABLE_AUDIO
+        uint8_t vol = val & 7;
+        if (vol != umac_volume) {
+            umac_volume = val & 7;
+            umac_audio_cfg(umac_volume, umac_sndres);
+        }
         oldval = val;
+#endif
 }
 
 static void     via_rb_changed(uint8_t val)
@@ -166,7 +176,13 @@ static void     via_rb_changed(uint8_t val)
         // 4 = mouse4 (in, mouse X2)
         // 3 = mouse7 (in, 0 = button pressed)
         // [2:0] = RTC controls
-        (void)val;
+#if ENABLE_AUDIO
+        uint8_t sndres = val >> 7;
+        if(sndres != umac_sndres) {
+            umac_sndres = sndres;
+            umac_audio_cfg(umac_volume, umac_sndres);
+        }
+#endif
 }
 
 static uint8_t  via_ra_in(void)
@@ -437,7 +453,13 @@ unsigned int    cpu_read_long_dasm(unsigned int address)
 void    FAST_FUNC(cpu_write_byte)(unsigned int address, unsigned int value)
 {
         if (IS_RAM(address)) {
-                RAM_WR8(CLAMP_RAM_ADDR(address), value);
+                address = CLAMP_RAM_ADDR(address);
+                RAM_WR8(address, value);
+#if ENABLE_AUDIO
+                if(IS_RAM_AUDIO_TRAP(address)) {
+                    umac_audio_trap();
+                }
+#endif
                 return;
         }
 
@@ -592,10 +614,35 @@ void    umac_opt_disassemble(int enable)
         disassemble = enable;
 }
 
-#define MOUSE_MAX_PENDING_PIX   30
+/* Provide mouse input (movement, button) data.
+ *
+ * X is positive going right; Y is positive going upwards.
+ */
+void    umac_absmouse(int x, int y, int button)
+{
+    if (!scc_get_mie()) return;
+#define MTemp_h 0x82a
+#define MTemp_v 0x828
+#define CrsrNew 0x8ce
+#define CrsrCouple 0x8cf
 
-static int pending_mouse_deltax = 0;
-static int pending_mouse_deltay = 0;
+        int oldx = RAM_RD16(MTemp_h);
+        int oldy = RAM_RD16(MTemp_v);
+
+        if(x != oldx) {
+            RAM_WR16(MTemp_h, x);
+        }
+
+        if (y != oldy) {
+            RAM_WR16(MTemp_v, y);
+        }
+
+        if(x != oldx || y != oldy) {
+            RAM_WR8(CrsrNew, RAM_RD8(CrsrCouple));
+        }
+
+        via_mouse_pressed = button;
+}
 
 /* Provide mouse input (movement, button) data.
  *
@@ -603,83 +650,22 @@ static int pending_mouse_deltay = 0;
  */
 void    umac_mouse(int deltax, int deltay, int button)
 {
-        pending_mouse_deltax += deltax;
-        pending_mouse_deltay += deltay;
-
-        /* Clamp if the UI has flooded with lots and lots of steps!
-         */
-        if (pending_mouse_deltax > MOUSE_MAX_PENDING_PIX)
-                pending_mouse_deltax = MOUSE_MAX_PENDING_PIX;
-        if (pending_mouse_deltax < -MOUSE_MAX_PENDING_PIX)
-                pending_mouse_deltax = -MOUSE_MAX_PENDING_PIX;
-        if (pending_mouse_deltay > MOUSE_MAX_PENDING_PIX)
-                pending_mouse_deltay = MOUSE_MAX_PENDING_PIX;
-        if (pending_mouse_deltay < -MOUSE_MAX_PENDING_PIX)
-                pending_mouse_deltay = -MOUSE_MAX_PENDING_PIX;
-
-        /* FIXME: The movement might take a little time, but this
-         * posts the button status immediately.  Probably OK, but the
-         * mismatch might be perceptible.
-         */
-        via_mouse_pressed = button;
-}
-
-static void     mouse_tick(void)
-{
-        /* Periodically, check if the mouse X/Y deltas are non-zero.
-         * If a movement is required, encode one step in X and/or Y
-         * and deduct from the pending delta.
-         *
-         * The step ultimately posts an SCC IRQ, so we _don't_ try to
-         * make any more steps while an IRQ is currently pending.
-         * (Currently, that means a previous step's DCD IRQ event
-         * hasn't yet been consumed by the OS handler.  In future, if
-         * SCC is extended with other IRQ types, then just checking
-         * the IRQ status is technically too crude, but should still
-         * be fine given the timeframes.)
-         */
-        if (pending_mouse_deltax == 0 && pending_mouse_deltay == 0)
-                return;
-
-        if (scc_irq_state == 1)
-                return;
-
-        static int old_dcd_a = 0;
-        static int old_dcd_b = 0;
-
-        /* Mouse X/Y quadrature signals are wired to:
-         *  VIA Port B[4] & SCC DCD_A for X
-         *  VIA Port B[5] & SCC DCD_B for Y
-         *
-         * As VIA mouse signals aren't sampled until IRQ, can do this
-         * in one step, toggling existing DCD states and setting VIA
-         * either equal or opposite to DCD:
-         */
-        int dcd_a = old_dcd_a;
-        int dcd_b = old_dcd_b;
-        int deltax = pending_mouse_deltax;
-        int deltay = pending_mouse_deltay;
-        uint8_t qb = via_quadbits;
-
-        if (deltax) {
-                dcd_a = !dcd_a;
-                qb = (qb & ~0x10) | ((deltax < 0) == dcd_a ? 0x10 : 0);
-                pending_mouse_deltax += (deltax > 0) ? -1 : 1;
-                MDBG("  px %d, oldpx %d", pending_mouse_deltax, deltax);
+    if (!scc_get_mie()) return;
+        if(deltax) {
+            int16_t temp_h = RAM_RD16(MTemp_h) + deltax;
+            RAM_WR16(MTemp_h, temp_h);
         }
 
         if (deltay) {
-                dcd_b = !dcd_b;
-                qb = (qb & ~0x20) | ((deltay < 0) == dcd_b ? 0x20 : 0);
-                pending_mouse_deltay += (deltay > 0) ? -1 : 1;
-                MDBG("  py %d, oldpy %d", pending_mouse_deltay, deltay);
+            int16_t temp_v = RAM_RD16(MTemp_v) - deltay;
+            RAM_WR16(MTemp_v, temp_v);
         }
-        MDBG("\n");
 
-        via_quadbits = qb;
-        old_dcd_a = dcd_a;
-        old_dcd_b = dcd_b;
-        scc_set_dcd(dcd_a, dcd_b);
+        if(deltax || deltay) {
+            RAM_WR8(CrsrNew, RAM_RD8(CrsrCouple));
+        }
+
+        via_mouse_pressed = button;
 }
 
 void    umac_reset(void)
@@ -705,13 +691,15 @@ int     umac_loop(void)
 {
         setjmp(main_loop_jb);
 
-        const int us = UMAC_EXECLOOP_QUANTUM;
-        m68k_execute(us*8);
-        global_time_us += us;
+        int cycles = UMAC_EXECLOOP_QUANTUM * 8;
+        cycles = via_limit_cycles(cycles);
+        int used_cycles = m68k_execute(cycles);
+        MDBG("Asked to execute %d cycles, actual %d cycles\n", cycles, used_cycles);
+        global_cycles += used_cycles;
+        global_time_us = global_cycles / 8;
 
         // Device polling
-        via_tick(global_time_us);
-        mouse_tick();
+        via_tick(used_cycles);
         kbd_check_work();
 
 	return sim_done;

src/rom.c

@@ -80,7 +80,7 @@ static uint32_t rom_get_version(uint8_t *rom_base)
         } while (0)
 
 
-static void     rom_patch_plusv3(uint8_t *rom_base)
+static int     rom_patch_plusv3(uint8_t *rom_base, int disp_width, int disp_height, int ram_size)
 {
         /* Inspired by patches in BasiliskII!
          */
@@ -100,138 +100,143 @@ static void     rom_patch_plusv3(uint8_t *rom_base)
          * - No IWM init
          * - new Sound?
          */
-#if UMAC_MEMSIZE > 128 && UMAC_MEMSIZE < 512
-        /* Hack to change memtop: try out a 256K Mac :) */
-        for (int i = 0x376; i < 0x37e; i += 2)
-                ROM_WR16(i, M68K_INST_NOP);
-        ROM_WR16(0x376, 0x2a7c); // moveal #RAM_SIZE, A5
-        ROM_WR16(0x378, RAM_SIZE >> 16);
-        ROM_WR16(0x37a, RAM_SIZE & 0xffff);
-        /* That overrides the probed memory size, but
-         * P_ChecksumRomAndTestMemory returns a failure code for
-         * things that aren't 128/512.  Skip that:
-         */
-        ROM_WR16(0x132, 0x6000); // Bra (was BEQ)
-        /* FIXME: We should also remove the memory probe routine, by
-         * allowing the ROM checksum to fail (it returns failure, then
-         * we carry on).  This avoids wild RAM addrs being accessed.
-         */
-#endif
+        if (ram_size > 128*1024 && ram_size < 512*1024) {
+                /* Hack to change memtop: try out a 256K Mac :) */
+                for (int i = 0x376; i < 0x37e; i += 2)
+                        ROM_WR16(i, M68K_INST_NOP);
+                ROM_WR16(0x376, 0x2a7c); // moveal #ram_size, A5
+                ROM_WR16(0x378, ram_size >> 16);
+                ROM_WR16(0x37a, ram_size & 0xffff);
+                /* That overrides the probed memory size, but
+                 * P_ChecksumRomAndTestMemory returns a failure code for
+                 * things that aren't 128/512.  Skip that:
+                 */
+                ROM_WR16(0x132, 0x6000); // Bra (was BEQ)
+                /* FIXME: We should also remove the memory probe routine, by
+                 * allowing the ROM checksum to fail (it returns failure, then
+                 * we carry on).  This avoids wild RAM addrs being accessed.
+                 */
 
-#if DISP_WIDTH != 512 || DISP_HEIGHT != 342
-#define SCREEN_SIZE                     (DISP_WIDTH*DISP_HEIGHT/8)
-#define SCREEN_DISTANCE_FROM_TOP        (SCREEN_SIZE + 0x380)
-#if (SCREEN_DISTANCE_FROM_TOP >= 65536)
-#error "rom.c: Screen res patching maths won't work for a screen this large"
-#endif
-#define SCREEN_BASE                     (0x400000-SCREEN_DISTANCE_FROM_TOP)
-#define SCREEN_BASE_L16                 (SCREEN_BASE & 0xffff)
-#define SBCOORD(x, y)                   (SCREEN_BASE + ((DISP_WIDTH/8)*(y)) + ((x)/8))
+                /* Fix up the sound buffer as used by BootBeep */
+                ROM_WR32(0x292, ram_size - 768);
+        }
 
-        /* Changing video res:
-         *
-         * Original 512*342 framebuffer is 0x5580 bytes; the screen
-         * buffer lands underneath sound/other buffers at top of mem,
-         * i,e, 0x3fa700 = 0x400000-0x5580-0x380.  So any new buffer
-         * will be placed (and read out from for the GUI) at
-         * MEM_TOP-0x380-SCREEN_SIZE.
-         *
-         * For VGA, size is 0x9600 bytes (0x2580 words)
-         */
+        if(disp_width != 512 || disp_height != 342) {
+                int screen_size = (disp_width*disp_height/8);
+                int screen_distance_from_top = screen_size + 0x380;
+                if (screen_distance_from_top >= 65536) {
+                    RERR("rom.c: screen res patching maths won't work for a screen this large");
+                    return -1;
+                }
+                int screen_base = 0x400000-screen_distance_from_top;
+                int screen_base_l16 = screen_base & 0xffff;
+#define SBCOORD(x, y)                   (screen_base + ((disp_width/8)*(y)) + ((x)/8))
 
-        /* We need some space, low down, to create jump-out-and-patch
-         * routines where a patch is too large to put inline.  The
-         * TestSoftware check at 0x42 isn't used:
-         */
-        ROM_WR16(0x42, 0x6000);                 /* bra */
-        ROM_WR16(0x44, 0x62-0x44);              /* offset */
-        /* Now 0x46-0x57 can be used */
-        unsigned int patch_0 = 0x46;
-        ROM_WR16(patch_0 + 0, 0x9bfc);          /* suba.l #imm32, A5 */
-        ROM_WR16(patch_0 + 2, 0);               /* (Could add more here) */
-        ROM_WR16(patch_0 + 4, SCREEN_DISTANCE_FROM_TOP);
-        ROM_WR16(patch_0 + 6, 0x6000);          /* bra */
-        ROM_WR16(patch_0 + 8, 0x3a4 - (patch_0 + 8));   /* Return to 3a4 */
+                /* Changing video res:
+                 *
+                 * Original 512*342 framebuffer is 0x5580 bytes; the screen
+                 * buffer lands underneath sound/other buffers at top of mem,
+                 * i,e, 0x3fa700 = 0x400000-0x5580-0x380.  So any new buffer
+                 * will be placed (and read out from for the GUI) at
+                 * MEM_TOP-0x380-screen_size.
+                 *
+                 * For VGA, size is 0x9600 bytes (0x2580 words)
+                 */
 
-        /* Magic screen-related locations in Mac Plus ROM 4d1f8172:
-         *
-         * 8c : screen base addr (usually 3fa700, now 3f6680)
-         * 148 : screen base addr again
-         * 164 : u32 screen address of crash Mac/critErr hex numbers
-         * 188 : u16 bytes per row (critErr)
-         * 194 : u16 bytes per row (critErr)
-         * 19c : u16 (bytes per row * 6)-1 (critErr)
-         * 1a4 : u32 screen address of critErr twiddly pattern
-         * 1ee : u16 screen sie in words minus one
-         * 3a2 : u16 screen size in bytes (BUT can't patch immediate)
-         * 474 : u16 bytes per row
-         * 494 : u16 screen y
-         * 498 : u16 screen x
-         * a0e : y
-         * a10 : x
-         * ee2 : u16 bytes per row minus 4 (tPutIcon)
-         * ef2 : u16 bytes per row (tPutIcon)
-         * 7e0 : u32 screen address of disk icon (240, 145)
-         * 7f2 : u32 screen address of disk icon's symbol (248, 160)
-         * f0c : u32 screen address of Mac icon (240, 145)
-         * f18 : u32 screen address of Mac icon's face (248, 151)
-         * f36 : u16 bytes per row minus 2 (mPutSymbol)
-         * 1cd1 : hidecursor's bytes per line
-         * 1d48 : xres minus 32 (for cursor rect clipping)
-         * 1d4e : xres minus 32
-         * 1d74 : y
-         * 1d93 : bytes per line (showcursor)
-         * 1e68 : y
-         * 1e6e : x
-         * 1e82 : y
-         */
-        ROM_WR16(0x8c, SCREEN_BASE_L16);
-        ROM_WR16(0x148, SCREEN_BASE_L16);
-        ROM_WR32(0x164, SBCOORD(DISP_WIDTH/2 - (48/2), DISP_HEIGHT/2 + 8));
-        ROM_WR16(0x188, DISP_WIDTH/8);
-        ROM_WR16(0x194, DISP_WIDTH/8);
-        ROM_WR16(0x19c, (6*DISP_WIDTH/8)-1);
-        ROM_WR32(0x1a4, SBCOORD(DISP_WIDTH/2 - 8, DISP_HEIGHT/2 + 8 + 8));
-        ROM_WR16(0x1ee, (SCREEN_SIZE/4)-1);
+                /* We need some space, low down, to create jump-out-and-patch
+                 * routines where a patch is too large to put inline.  The
+                 * TestSoftware check at 0x42 isn't used:
+                 */
+                ROM_WR16(0x42, 0x6000);                 /* bra */
+                ROM_WR16(0x44, 0x62-0x44);              /* offset */
+                /* Now 0x46-0x57 can be used */
+                unsigned int patch_0 = 0x46;
+                ROM_WR16(patch_0 + 0, 0x9bfc);          /* suba.l #imm32, A5 */
+                ROM_WR16(patch_0 + 2, 0);               /* (Could add more here) */
+                ROM_WR16(patch_0 + 4, screen_distance_from_top);
+                ROM_WR16(patch_0 + 6, 0x6000);          /* bra */
+                ROM_WR16(patch_0 + 8, 0x3a4 - (patch_0 + 8));   /* Return to 3a4 */
 
-        ROM_WR32(0xf0c, SBCOORD(DISP_WIDTH/2 - 16, DISP_HEIGHT/2 - 26));
-        ROM_WR32(0xf18, SBCOORD(DISP_WIDTH/2 - 8, DISP_HEIGHT/2 - 20));
-        ROM_WR32(0x7e0, SBCOORD(DISP_WIDTH/2 - 16, DISP_HEIGHT/2 - 26));
-        ROM_WR32(0x7f2, SBCOORD(DISP_WIDTH/2 - 8, DISP_HEIGHT/2 - 11));
+                /* Magic screen-related locations in Mac Plus ROM 4d1f8172:
+                 *
+                 * 8c : screen base addr (usually 3fa700, now 3f6680)
+                 * 148 : screen base addr again
+                 * 164 : u32 screen address of crash Mac/critErr hex numbers
+                 * 188 : u16 bytes per row (critErr)
+                 * 194 : u16 bytes per row (critErr)
+                 * 19c : u16 (bytes per row * 6)-1 (critErr)
+                 * 1a4 : u32 screen address of critErr twiddly pattern
+                 * 1ee : u16 screen sie in words minus one
+                 * 3a2 : u16 screen size in bytes (BUT can't patch immediate)
+                 * 474 : u16 bytes per row
+                 * 494 : u16 screen y
+                 * 498 : u16 screen x
+                 * a0e : y
+                 * a10 : x
+                 * ee2 : u16 bytes per row minus 4 (tPutIcon)
+                 * ef2 : u16 bytes per row (tPutIcon)
+                 * 7e0 : u32 screen address of disk icon (240, 145)
+                 * 7f2 : u32 screen address of disk icon's symbol (248, 160)
+                 * f0c : u32 screen address of Mac icon (240, 145)
+                 * f18 : u32 screen address of Mac icon's face (248, 151)
+                 * f36 : u16 bytes per row minus 2 (mPutSymbol)
+                 * 1cd1 : hidecursor's bytes per line
+                 * 1d48 : xres minus 32 (for cursor rect clipping)
+                 * 1d4e : xres minus 32
+                 * 1d74 : y
+                 * 1d93 : bytes per line (showcursor)
+                 * 1e68 : y
+                 * 1e6e : x
+                 * 1e82 : y
+                 */
+                ROM_WR16(0x8c, screen_base_l16);
+                ROM_WR16(0x148, screen_base_l16);
+                ROM_WR32(0x164, SBCOORD(disp_width/2 - (48/2), disp_height/2 + 8));
+                ROM_WR16(0x188, disp_width/8);
+                ROM_WR16(0x194, disp_width/8);
+                ROM_WR16(0x19c, (6*disp_width/8)-1);
+                ROM_WR32(0x1a4, SBCOORD(disp_width/2 - 8, disp_height/2 + 8 + 8));
+                ROM_WR16(0x1ee, (screen_size/4)-1);
 
-        /* Patch "SubA #$5900, A5" to subtract 0x9880.
-         * However... can't just patch the int16 immediate, as that's
-         * sign-extended (and we end up with a subtract-negative,
-         * i.e. an add).  There isn't space here to turn it into sub.l
-         * so add some rigamarole to branch to some bytes stolen at
-         * patch_0 up above.
-         */
-        ROM_WR16(0x3a0, 0x6000);                /* bra */
-        ROM_WR16(0x3a2, patch_0 - 0x3a2);       /* ...to patch0, returns at 0x3a4 */
+                ROM_WR32(0xf0c, SBCOORD(disp_width/2 - 16, disp_height/2 - 26));
+                ROM_WR32(0xf18, SBCOORD(disp_width/2 - 8, disp_height/2 - 20));
+                ROM_WR32(0x7e0, SBCOORD(disp_width/2 - 16, disp_height/2 - 26));
+                ROM_WR32(0x7f2, SBCOORD(disp_width/2 - 8, disp_height/2 - 11));
 
-        ROM_WR16(0x474, DISP_WIDTH/8);
-        ROM_WR16(0x494, DISP_HEIGHT);
-        ROM_WR16(0x498, DISP_WIDTH);
-        ROM_WR16(0xa0e, DISP_HEIGHT);           /* copybits? */
-        ROM_WR16(0xa10, DISP_WIDTH);
-        ROM_WR16(0xee2, (DISP_WIDTH/8)-4);      /* tPutIcon bytes per row, minus 4 */
-        ROM_WR16(0xef2, DISP_WIDTH/8);          /* tPutIcon bytes per row */
-        ROM_WR16(0xf36, (DISP_WIDTH/8)-2);      /* tPutIcon bytes per row, minus 2 */
-        ROM_WR8(0x1cd1, DISP_WIDTH/8);          /* hidecursor */
-        ROM_WR16(0x1d48, DISP_WIDTH-32);        /* 1d46+2 was originally 512-32 rite? */
-        ROM_WR16(0x1d4e, DISP_WIDTH-32);        /* 1d4c+2 is 480, same */
-        ROM_WR16(0x1d6e, DISP_HEIGHT-16);       /* showcursor (YESS fixed Y crash bug!) */
-        ROM_WR16(0x1d74, DISP_HEIGHT);          /* showcursor */
-        ROM_WR8(0x1d93, DISP_WIDTH/8);          /* showcursor */
-        ROM_WR16(0x1e68, DISP_HEIGHT);          /* mScrnSize */
-        ROM_WR16(0x1e6e, DISP_WIDTH);           /* mScrnSize */
-        ROM_WR16(0x1e82, DISP_HEIGHT);          /* tScrnBitMap */
+                /* Patch "SubA #$5900, A5" to subtract 0x9880.
+                 * However... can't just patch the int16 immediate, as that's
+                 * sign-extended (and we end up with a subtract-negative,
+                 * i.e. an add).  There isn't space here to turn it into sub.l
+                 * so add some rigamarole to branch to some bytes stolen at
+                 * patch_0 up above.
+                 */
+                ROM_WR16(0x3a0, 0x6000);                /* bra */
+                ROM_WR16(0x3a2, patch_0 - 0x3a2);       /* ...to patch0, returns at 0x3a4 */
+
+                ROM_WR16(0x474, disp_width/8);
+                ROM_WR16(0x494, disp_height);
+                ROM_WR16(0x498, disp_width);
+                ROM_WR16(0xa0e, disp_height);           /* copybits? */
+                ROM_WR16(0xa10, disp_width);
+                ROM_WR16(0xee2, (disp_width/8)-4);      /* tPutIcon bytes per row, minus 4 */
+                ROM_WR16(0xef2, disp_width/8);          /* tPutIcon bytes per row */
+                ROM_WR16(0xf36, (disp_width/8)-2);      /* tPutIcon bytes per row, minus 2 */
+                ROM_WR8(0x1cd1, disp_width/8);          /* hidecursor */
+                ROM_WR16(0x1d48, disp_width-32);        /* 1d46+2 was originally 512-32 rite? */
+                ROM_WR16(0x1d4e, disp_width-32);        /* 1d4c+2 is 480, same */
+                ROM_WR16(0x1d6e, disp_height-16);       /* showcursor (YESS fixed Y crash bug!) */
+                ROM_WR16(0x1d74, disp_height);          /* showcursor */
+                ROM_WR8(0x1d93, disp_width/8);          /* showcursor */
+                ROM_WR16(0x1e68, disp_height);          /* mScrnSize */
+                ROM_WR16(0x1e6e, disp_width);           /* mScrnSize */
+                ROM_WR16(0x1e82, disp_height);          /* tScrnBitMap */
+        }
 
         /* FIXME: Welcome To Macintosh is drawn at the wrong position. Find where that's done. */
-#endif
+        return 0;
 }
 
-int      rom_patch(uint8_t *rom_base)
+static int      rom_patch1(uint8_t *rom_base, int disp_width, int disp_height, int mem_size)
 {
         uint32_t v = rom_get_version(rom_base);
         int r = -1;
@@ -239,8 +244,7 @@ int      rom_patch(uint8_t *rom_base)
          */
         switch(v) {
         case ROM_PLUSv3_VERSION:
-                rom_patch_plusv3(rom_base);
-                r = 0;
+                r = rom_patch_plusv3(rom_base, disp_width, disp_height, mem_size);
                 break;
 
         default:
@@ -250,3 +254,103 @@ int      rom_patch(uint8_t *rom_base)
         return r;
 }
 
+#if defined(UMAC_STANDALONE_PATCHER)
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+int main(int argc, char **argv) {
+        uint8_t *rom_base;
+        char *rom_filename = "4D1F8172 - MacPlus v3.ROM";
+        char *rom_dump_filename = NULL; // Raw bytes
+        char *rom_header_filename = NULL; // C header
+        int ch;
+        int disp_width = 512;
+        int disp_height = 342;
+        int ram_size = 128;
+
+        while ((ch = getopt(argc, argv, "vm:r:w:W:")) != -1) {
+                switch (ch) {
+                case 'v':
+                        disp_width = 640;
+                        disp_height = 480;
+                        break;
+                case 'm':
+                        ram_size = atoi(optarg);
+                        break;
+                case 'r':
+                        rom_filename = strdup(optarg);
+                        break;
+                case 'W':
+                        rom_dump_filename = strdup(optarg);
+                        break;
+                case 'w':
+                        rom_header_filename = strdup(optarg);
+                        break;
+                case '?':
+                        abort();
+                }
+        }
+        if (!rom_dump_filename && !rom_header_filename) {
+                printf("Must specify either a -W (binary) or -w (C header) output file");
+                abort();
+        }
+        printf("Opening ROM '%s'\n", rom_filename);
+        int ofd = open(rom_filename, O_RDONLY);
+        if (ofd < 0) {
+                perror("ROM");
+                return 1;
+        }
+
+        struct stat sb;
+        fstat(ofd, &sb);
+        off_t _rom_size = sb.st_size;
+        rom_base = mmap(0, _rom_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, ofd, 0);
+        if (rom_base == MAP_FAILED) {
+                printf("Can't mmap ROM!\n");
+                return 1;
+        }
+        if (rom_patch1(rom_base, disp_width, disp_height, ram_size*1024)) {
+                printf("Failed to patch ROM\n");
+                return 1;
+        }
+        if (rom_dump_filename) {
+                int rfd = open(rom_dump_filename, O_CREAT | O_TRUNC | O_RDWR, 0655);
+                if (rfd < 0) {
+                        perror("ROM dump");
+                        return 1;
+                }
+                ssize_t written = write(rfd, rom_base, _rom_size);
+                if (written < 0) {
+                        perror("ROM dump write");
+                        return 1;
+                }
+                if (written < _rom_size) {
+                        printf("*** WARNING: Short write to %s!\n",
+                               rom_dump_filename);
+                } else {
+                        printf("Dumped ROM to %s\n", rom_dump_filename);
+                }
+                close(rfd);
+        }
+        if (rom_header_filename) {
+            FILE *ofd = fopen(rom_header_filename, "w");
+            if (!ofd) { perror("fopen"); abort(); }
+            for(off_t i=0; i<_rom_size; i++) {
+                fprintf(ofd, "%d,", rom_base[i]);
+                if(i % 16 == 15) fprintf(ofd, "\n");
+            }
+            fprintf(ofd, "\n");
+            printf("Dumped ROM to %s as header\n", rom_header_filename);
+            fclose(ofd);
+        }
+}
+#else
+int      rom_patch(uint8_t *rom_base) {
+        return rom_patch1(rom_base, DISP_WIDTH, DISP_HEIGHT, UMAC_MEMSIZE * 1024);
+}
+#endif

src/scc.c

@@ -126,6 +126,8 @@ static void     scc_wr3(int AnB, uint8_t data)
         }
 }
 
+int scc_get_mie() { return scc_mie; }
+
 // WR9: Master Interrupt control and reset commands
 static void     scc_wr9(uint8_t data)
 {

src/unix_main.c

@@ -27,6 +27,7 @@
  * SOFTWARE.
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <getopt.h>
@@ -35,6 +36,9 @@
 #include <sys/time.h>
 #include <string.h>
 #include <unistd.h>
+#if ENABLE_AUDIO
+#include <stdatomic.h>
+#endif
 #include "SDL.h"
 
 #include "rom.h"
@@ -78,6 +82,42 @@ static void     copy_fb(uint32_t *fb_out, uint8_t *fb_in)
         }
 }
 
+#if ENABLE_AUDIO
+// audio_callback is called from a thread, so pending_v_retrace can't be a regular variable
+atomic_int pending_v_retrace;
+static int volscale;
+uint8_t *audio_base;
+
+int16_t audio[370];
+
+void umac_audio_cfg(int umac_volume, int umac_sndres) {
+        volscale = umac_sndres ? 0 : 65536 * umac_volume / 7;
+}
+
+void umac_audio_trap() {
+    int32_t  offset = 128;
+    uint16_t *audiodata = (uint16_t*)audio_base;
+    int scale = volscale;
+    if (!scale) {
+        memset(audio, 0, sizeof(audio));
+        return;
+    }
+    int16_t *stream = audio;
+    for(int i=0; i<370; i++) {
+        int32_t a = (*audiodata++ & 0xff) - offset;
+        a = (a * scale) >> 8;
+        *stream++ = a;
+    }
+}
+
+static void audio_callback(void *userdata, Uint8 *stream_in, int len_bytes) {
+        (void) userdata;
+        assert(len_bytes == sizeof(audio));
+        atomic_store(&pending_v_retrace, 1);
+        memcpy(stream_in, audio, sizeof(audio));
+}
+#endif
+
 /**********************************************************************/
 
 /* The emulator core expects to be given ROM and RAM pointers,
@@ -232,7 +272,11 @@ int     main(int argc, char *argv[])
         SDL_Renderer *renderer;
         SDL_Texture *texture;
 
-        SDL_Init(SDL_INIT_VIDEO);
+        SDL_Init(SDL_INIT_VIDEO
+#if ENABLE_AUDIO
+                | SDL_INIT_AUDIO
+#endif
+);
         SDL_Window *window = SDL_CreateWindow("umac",
                                               SDL_WINDOWPOS_UNDEFINED,
                                               SDL_WINDOWPOS_UNDEFINED,
@@ -243,8 +287,14 @@ int     main(int argc, char *argv[])
                 perror("SDL window");
                 return 1;
         }
-        SDL_SetWindowGrab(window, SDL_TRUE);
-        SDL_SetRelativeMouseMode(SDL_TRUE);
+
+        static const int absmouse = 1;
+        if (!absmouse) {
+            SDL_SetWindowGrab(window, SDL_TRUE);
+            SDL_SetRelativeMouseMode(SDL_TRUE);
+        } else {
+            SDL_ShowCursor(SDL_DISABLE);
+        }
 
         SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
 
@@ -264,25 +314,55 @@ int     main(int argc, char *argv[])
                 return 1;
         }
 
+#if ENABLE_AUDIO
+        SDL_AudioSpec desired, obtained;
+
+        audio_base = (uint8_t*)ram_base + umac_get_audio_offset();
+
+        SDL_zero(desired);
+        desired.freq = 22256; // wat
+        desired.channels = 1;
+        desired.samples = 370;
+        desired.userdata = (uint8_t*)ram_base + umac_get_audio_offset();
+        desired.callback = audio_callback;
+        desired.format = AUDIO_S16;
+
+        SDL_AudioDeviceID audio_device = SDL_OpenAudioDevice(NULL, 0, &desired, &obtained, 0);
+        if (!audio_device) {
+                char buf[500];
+                SDL_GetErrorMsg(buf, sizeof(buf));
+                printf("SDL audio_deviceSDL_GetError() -> %s\n", buf);
+                return 1;
+        }
+#endif
+
         ////////////////////////////////////////////////////////////////////////
         // Emulator init
 
         umac_init(ram_base, rom_base, discs);
         umac_opt_disassemble(opt_disassemble);
 
+#if ENABLE_AUDIO
+        // Default state is paused, this unpauses it
+        SDL_PauseAudioDevice(audio_device, 0);
+#endif
+
         ////////////////////////////////////////////////////////////////////////
         // Main loop
 
         int done = 0;
         int mouse_button = 0;
+#if !ENABLE_AUDIO
         uint64_t last_vsync = 0;
+#endif
         uint64_t last_1hz = 0;
         do {
                 struct timeval tv_now;
                 SDL_Event event;
                 int mousex = 0;
                 int mousey = 0;
-
+                int send_mouse = 0;
+                static int absmousex, absmousey;
                 if (SDL_PollEvent(&event)) {
                         switch (event.type) {
                         case SDL_QUIT:
@@ -299,21 +379,32 @@ int     main(int argc, char *argv[])
                         } break;
 
                         case SDL_MOUSEMOTION:
+                                send_mouse = 1;
+                                absmousex = event.motion.x / DISP_SCALE;
+                                absmousey = event.motion.y / DISP_SCALE;
                                 mousex = event.motion.xrel;
                                 mousey = -event.motion.yrel;
                                 break;
 
                         case SDL_MOUSEBUTTONDOWN:
+                                send_mouse = 1;
                                 mouse_button = 1;
                                 break;
 
                         case SDL_MOUSEBUTTONUP:
+                                send_mouse = 1;
                                 mouse_button = 0;
                                 break;
                         }
                 }
 
-                umac_mouse(mousex, mousey, mouse_button);
+                if (send_mouse) {
+                    if(absmouse) {
+                        umac_absmouse(absmousex, absmousey, mouse_button);
+                    } else {
+                        umac_mouse(mousex, mousey, mouse_button);
+                    }
+                }
 
                 done |= umac_loop();
 
@@ -321,12 +412,27 @@ int     main(int argc, char *argv[])
                 uint64_t now_usec = (tv_now.tv_sec * 1000000) + tv_now.tv_usec;
 
                 /* Passage of time: */
-                if ((now_usec - last_vsync) >= 16667) {
+#if ENABLE_AUDIO
+                int do_v_retrace = atomic_exchange(&pending_v_retrace, 0);
+#else
+                int do_v_retrace = (now_usec - last_vsync) >= 16667;
+#endif
+                if (do_v_retrace) {
                         umac_vsync_event();
-                        last_vsync = now_usec;
 
-                        /* Cheapo framerate limiting: */
                         copy_fb(framebuffer, ram_get_base() + umac_get_fb_offset());
+
+        uint16_t *audioptr = (uint16_t*)((uint8_t*)ram_base + umac_get_audio_offset());
+        for(int i=0; i<DISP_HEIGHT; i++) {
+            int d = *audioptr++ & 0xff;
+            for(int j=0; j<8; j++) {
+                if (d & (1 << j)) {
+                    uint32_t fbdata = framebuffer[j + i * DISP_WIDTH];
+                    fbdata = (fbdata & ~0xff) | ((d & (1 << j)) ? 0xff : 0);
+                    framebuffer[j + i * DISP_WIDTH] = fbdata;
+                }
+            }
+        }
                         SDL_UpdateTexture(texture, NULL, framebuffer,
                                           DISP_WIDTH * sizeof (Uint32));
                         /* Scales texture up to window size */

src/via.c

@@ -29,6 +29,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 
+#include "m68kcpu.h"
 #include "via.h"
 
 #ifdef DEBUG
@@ -47,7 +48,8 @@
 #define VIA_T1CH        5
 #define VIA_T1LL        6
 #define VIA_T1LH        7
-#define VIA_T2CL        8
+#define VIA_T2CL        8 // write latch
+#define VIA_T2LL        8 // read counter
 #define VIA_T2CH        9
 #define VIA_SR          10
 #define VIA_ACR         11
@@ -56,6 +58,7 @@
 #define  VIA_IRQ_CA     0x01
 #define  VIA_IRQ_CB     0x02
 #define  VIA_IRQ_SR     0x04
+#define  VIA_IRQ_T2     0x20
 #define VIA_IER         14
 #define VIA_RA_ALT      15 // No-handshake version
 
@@ -68,7 +71,7 @@ static const char *dbg_regnames[] = {
         "VIA_T1CH",
         "VIA_T1LL",
         "VIA_T1LH",
-        "VIA_T2CL",
+        "VIA_T2xL",
         "VIA_T2CH",
         "VIA_SR",
         "VIA_ACR",
@@ -84,6 +87,8 @@ static int irq_status = 0;
 static uint8_t irq_active = 0;
 static uint8_t irq_enable = 0;
 
+static uint16_t via_t2c;
+
 void    via_init(struct via_cb *cb)
 {
         for (int i = 0; i < 16; i++)
@@ -224,6 +229,24 @@ void    via_write(unsigned int address, uint8_t data)
         case VIA_PCR:
                 VDBG("VIA PCR %02x\n", data);
                 break;
+        case VIA_ACR:
+                if(data & 0xe0)
+                    VDBG("VIA ACR %02x\n", data);
+                break;
+        case VIA_T2CH:
+                VDBG("VIA T2CH %02x [ACR=%02x]\n", data, via_regs[VIA_ACR]);
+                // writing T2CH loads the low 8 bits from the latch
+                via_t2c = via_regs[VIA_T2CL] | (data << 8);
+                VDBG("VIA Loaded timer 2 with %d cycles\n", via_t2c);
+                if(via_t2c > 0 && GET_CYCLES() > via_t2c) {
+                    SET_CYCLES(via_t2c);
+                }
+                // writing T2CH clears associated IRQ flag
+                irq_active &= ~VIA_IRQ_T2;
+                break;
+        case VIA_T2CL:
+                VDBG("VIA T2CL %02x [ACR=%02x]\n", data, via_regs[VIA_ACR]);
+                break;
         default:
                 VDBG("[VIA: unhandled WR %02x to %s (reg 0x%x)]\n", data, rname, r);
         }
@@ -282,6 +305,14 @@ uint8_t via_read(unsigned int address)
         case VIA_IFR:
                 data = via_read_ifr();
                 break;
+
+        case VIA_T2LL:
+                // not right, should be reduced according to cycles since
+                // quantum began
+                data = via_t2c & 0xff;
+                // reading T2LL clears associated IRQ flag
+                irq_active &= ~VIA_IRQ_T2;
+                break;
         default:
                 VDBG("[VIA: unhandled RD of %s (reg 0x%x)]\n", rname, r);
         }
@@ -290,10 +321,29 @@ uint8_t via_read(unsigned int address)
         return data;
 }
 
+int via_limit_cycles(int cycles_in) {
+    if (via_t2c > 0 && via_t2c < cycles_in) {
+        return via_t2c;
+    }
+    return cycles_in;
+}
+
 /* Time param in us */
-void    via_tick(uint64_t time)
+void    via_tick(int cycles)
 {
-        (void)time;
+        int i = via_t2c;
+        if (i) {
+            int old = i;
+            i -= cycles;
+            VDBG("Timer count down %d -> %d\n", old, i);
+            if (i <= 0) {
+                i = 0;
+                VDBG("[VIA T2 reached zero, IRQ pending]\n");
+                // irq_active |= VIA_IRQ_T2;
+                via_assess_irq();
+            }
+            via_t2c = i;
+        }
         // FIXME: support actual timers.....!
 }