Fix sign extensions from vipRead() and busReadMisc()

core/bus.c

@@ -153,12 +153,18 @@ static void busRead(VB *sim, uint32_t address, int type, int32_t *value) {
 
         case 0: /* VIP */
             vipRead(sim, address, type, value);
+            switch (type) {
+                case VB_S8 : *value = (int8_t ) *value; break;
+                case VB_S16: *value = (int16_t) *value; break;
+            }
             break;
 
         case 1: break; /* VSU */
 
         case 2: /* Misc. I/O */
             *value = busReadMisc(sim, address, type);
+            if (type == VB_S8)
+                *value = (int8_t) *value;
             break;
 
         case 3: break; /* Unmapped */

core/cpu.c

@@ -1637,6 +1637,7 @@ static void cpuSUBF_S(VB *sim) {
 /* TRAP */
 static void cpuTRAP(VB *sim) {
     sim->cpu.clocks += cpuClocks(15);
+    sim->cpu.pc     += 2;
     cpuThrow(sim, 0xFFA0 + cpuGetImm5U(sim));
 }
 

core/timer.c

@@ -117,7 +117,7 @@ static void tmrWriteControl(VB *sim, uint8_t value) {
     if (
         !sim->tmr.t_clk_sel &&
         (value & 0x10)      && /* T-Clk-Sel */
-        sim->tmr.tick20 != 4
+        sim->tmr.tick20 != 0
     ) {
         tmrUpdate(sim, sim->tmr.counter == 0 ?
             sim->tmr.reload : sim->tmr.counter - 1);

core/vb.c

@@ -312,6 +312,7 @@ struct VB {
             int      frame;    /* FRMCYC counter */
             int32_t  halfword; /* Current output halfword offset */
             int      step;     /* Processing phase */
+            uint8_t  toggle;   /* Switch frame buffers next frame */
             uint32_t until;    /* Clocks until interrupt condition */
         } xp;
 
@@ -326,6 +327,7 @@ struct VB {
         uint16_t spt[4];     /* Object control */
 
         /* Rendering shadow memory */
+        uint8_t  buffer;            /* Output buffer */
         uint16_t halfwords[384*28]; /* Output timing by 1x8 halfword */
         Pixels   output[2];         /* Output images, row-major */
         Pixels   shadow;            /* Drawing shadow image, column-major */
@@ -632,7 +634,7 @@ VBAPI void vbGetPixels(VB *sim, void *left, int leftStrideX, int leftStrideY,
             continue;
 
         /* Transfer pixels to the destination */
-        src = sim->vip.output[sim->vip.dp.buffer ^ 1][i];
+        src = sim->vip.output[sim->vip.buffer][i];
         for (y = 0; y < 224; y++, dest += yStride)
         for (x = offset = 0; x < 384; x++, offset += xStride)
             dest[offset] = *src++;

core/vb.h

@@ -126,7 +126,6 @@ typedef int  (*vbOnWrite    )(VB *sim, uint32_t address, int type, int32_t *valu
 
 VBAPI int           vbEmulate             (VB *sim, uint32_t *clocks);
 VBAPI int           vbEmulateEx           (VB **sims, unsigned count, uint32_t *clocks);
-VBAPI void*         vbGetCallback         (VB *sim, int id);
 VBAPI void*         vbGetCartRAM          (VB *sim, uint32_t *size);
 VBAPI void*         vbGetCartROM          (VB *sim, uint32_t *size);
 VBAPI vbOnException vbGetExceptionCallback(VB *sim);

core/vip.c

@@ -598,7 +598,7 @@ static void vipTransferColumn(VB *sim, int32_t eye) {
 
     /* Select destination address in host memory */
     dest = &sim->vip.output
-        [sim->vip.dp.buffer][eye][sim->vip.dp.column];
+        [sim->vip.buffer ^ 1][eye][sim->vip.dp.column];
 
     /* Output is disabled */
     if (!sim->vip.dp.enabled) {
@@ -656,11 +656,12 @@ static int vipEmulateDisplay(VB *sim, uint32_t clocks) {
                 /* Game frame */
                 if (sim->vip.xp.xpen) {
                     if (sim->vip.xp.frame >= sim->vip.frmcyc) {
-                        sim->vip.xp.frame = 0;
+                        sim->vip.dp.buffer ^= sim->vip.xp.toggle;
+                        sim->vip.xp.frame   = 0;
+                        sim->vip.xp.toggle  = 0;
 
                         /* Initiate drawing procedure */
                         if (sim->vip.xp.step == 0) {
-                            sim->vip.dp.buffer  ^= 1;
                             sim->vip.xp.enabled  = 1;
                             sim->vip.xp.overtime = 0;
                             sim->vip.xp.step     = 1;
@@ -767,6 +768,7 @@ static int vipEmulateDisplay(VB *sim, uint32_t clocks) {
             /* 18ms-20ms - Idle */
 
             case 8: /* 20ms - Display interval complete */
+                sim->vip.buffer ^= 1;
                 sim->vip.dp.step = 0;
                 if (vipOnFrame(sim))
                     return 1;
@@ -1264,6 +1266,7 @@ static void vipEmulateDrawing(VB *sim, uint32_t clocks) {
             case 4: /* Drawing complete */
                 sim->vip.xp.enabled = 0;
                 sim->vip.xp.step    = 0;
+                sim->vip.xp.toggle  = 1;
                 if (sim->vip.dp.buffer == 0)
                      sim->vip.xp.f1bsy = 0;
                 else sim->vip.xp.f0bsy = 0;
@@ -1330,11 +1333,11 @@ static void vipRead(VB *sim, uint32_t address, int type, int32_t *value) {
 
 /* Simulate a hardware reset */
 static void vipReset(VB *sim) {
-    Cell      *cell;  /* BG map cell state */
-    Character *chr;   /* Character state */
-    Object    *obj;   /* Object state */
-    World     *world; /* World state */
-    int        x, y;  /* Iterators */
+    Cell      *cell;    /* BG map cell state */
+    Character *chr;     /* Character state */
+    Object    *obj;     /* Object state */
+    World     *world;   /* World state */
+    int        x, y, z; /* Iterators */
 
     /* Normal */
     sim->vip.intenb   = 0x0000;
@@ -1424,6 +1427,13 @@ static void vipReset(VB *sim) {
     sim->vip.xp.sbcount  = 0;
     sim->vip.xp.sbout    = 0;
 
+    /* Other */
+    sim->vip.buffer = 0;
+    for (x = 0; x < 2; x++)
+    for (y = 0; y < 2; y++)
+    for (z = 0; z < 384*224; z++)
+        sim->vip.output[x][y][z] = 0;
+
     /* Display processor other */
     sim->vip.dp.brt[0] = 0;
     sim->vip.dp.buffer = 0; /* TODO: Hardware might actually do this */
@@ -1434,6 +1444,7 @@ static void vipReset(VB *sim) {
     /* Pixel processor other */
     sim->vip.xp.clocks = 0;
     sim->vip.xp.step   = 0;
+    sim->vip.xp.toggle = 0;
     sim->vip.xp.until  = 0;
 }
 

web/Core.js

@@ -87,11 +87,8 @@ new class Core {
             this.sims.set(sim.pointer, sim);
 
             // Video
-            sim.pixels = this.#noalloc(
-                this.GetExtPixels(sim.pointer),
-                384*224*4, sim, "pixels", Uint8ClampedArray
-            );
-            sim.image = new ImageData(sim.pixels, 384, 224);
+            sim.pixels = this.#getPixels(sim);
+            sim.image  = new ImageData(sim.pixels, 384, 224);
 
             // Audio
             sim.samples = this.#noalloc(
@@ -364,8 +361,10 @@ new class Core {
             this.mallocs.set(buffer.pointer, buffer);
             this.#updateTarget(buffer);
         }
-        for (let sim of this.sims)
-            sim.image = new ImageData(sim.pixels, 384, 224);
+        for (let sim of this.sims.values()) {
+            sim.pixels = this.#getPixels(sim);
+            sim.image  = new ImageData(sim.pixels, 384, 224);
+        }
     }
 
 
@@ -436,6 +435,14 @@ new class Core {
         this.Realloc(buffer.pointer, 0);
     }
 
+    // Register a sim's pixel buffer
+    #getPixels(sim) {
+        return this.#noalloc(
+            this.GetExtPixels(sim.pointer),
+            384*224*4, sim, "pixels", Uint8ClampedArray
+        );
+    }
+
     // Allocate memory in WebAssembly and register the buffer
     #malloc(count, target = null, assign = null, type = Uint8ClampedArray) {
         return this.#noalloc(