Adjust GAMESTART logic, consolidate VIP sign-extensions

core/bus.c

@@ -159,6 +159,8 @@ static void busRead(VB *sim, uint32_t address, int type, int32_t *value) {
 
         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

@@ -91,11 +91,6 @@
 #define CPU_XORBSU   82
 #define CPU_XORNBSU  83
 
-/* Functional operand types */
-#define CPU_LITERAL  0
-#define CPU_MEMORY   1
-#define CPU_REGISTER 2
-
 /* Bit string operations */
 #define CPU_AND_BS  0
 #define CPU_ANDN_BS 1
@@ -1642,6 +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

@@ -5,6 +5,15 @@
 
 /***************************** Module Functions ******************************/
 
+/* Compute clocks until the next decrement to zero */
+static uint32_t tmrGetUntil(VB *sim) {
+    uint32_t fullTick = sim->tmr.t_clk_sel ? 400 : 2000;
+    uint32_t thisTick = sim->tmr.clocks +
+        (sim->tmr.t_clk_sel ? 0 : 400 * (4 - sim->tmr.tick20));
+    return thisTick + fullTick *
+        (sim->tmr.counter == 0 ? sim->tmr.reload : sim->tmr.counter - 1);
+}
+
 /* Update the counter to a new value */
 static void tmrUpdate(VB *sim, uint16_t value) {
     if (value == 0 && sim->tmr.counter != 0) {
@@ -23,10 +32,6 @@ static void tmrUpdate(VB *sim, uint16_t value) {
 /* Process component */
 static void tmrEmulate(VB *sim, uint32_t clocks) {
 
-    /* Timer is disabled */
-    if (!sim->tmr.t_enb)
-        return;
-
     /* Process all clocks */
     for (;;) {
 
@@ -40,13 +45,20 @@ static void tmrEmulate(VB *sim, uint32_t clocks) {
         /* Advance forward the component's number of clocks */
         clocks          -= sim->tmr.clocks;
         sim->tmr.until  -= sim->tmr.clocks;
-        sim->tmr.clocks = sim->tmr.t_clk_sel ? 400 : 2000;
+        sim->tmr.clocks  = 400;
+        sim->tmr.tick20 += sim->tmr.tick20 == 4 ? -4 : 1;
+
+        /* Do not decrement counter */
+        if (
+            !sim->tmr.t_enb ||
+            (!sim->tmr.t_clk_sel && sim->tmr.tick20 != 0)
+        ) continue;
 
         /* Advance to the next counter value */
         tmrUpdate(sim, sim->tmr.counter == 0 ?
             sim->tmr.reload : sim->tmr.counter - 1);
         if (sim->tmr.counter == 0)
-            sim->tmr.until = sim->tmr.clocks * ((uint32_t)sim->tmr.reload + 1);
+            sim->tmr.until = tmrGetUntil(sim);
     }
 
 }
@@ -71,8 +83,10 @@ static void tmrReset(VB *sim) {
     sim->tmr.z_stat    = 0;
 
     /* Other */
+    sim->tmr.clocks  = 400;
     sim->tmr.counter = 0xFFFF;
     sim->tmr.reload  = 0x0000;
+    sim->tmr.tick20  = 0;
 }
 
 /* Determine how many clocks are guaranteed to process */
@@ -88,14 +102,27 @@ static void tmrWriteControl(VB *sim, uint8_t value) {
     if (
         (value & 0x04) && /* Z-Stat-Clr */
         (
-            sim->tmr.counter != 0 ||
+            !sim->tmr.t_enb ||
-            !sim->tmr.t_enb
+            (
+                sim->tmr.counter != 0 &&
+                !(value & 0x01) /* T-Enb */
+            )
         )
     ) {
         sim->tmr.z_stat = sim->tmr.counter != 0;
         sim->cpu.irq   &= ~0x0002;
     }
 
+    /* Hardware bug: decrement on switch to 20us mode */
+    if (
+        !sim->tmr.t_clk_sel &&
+        (value & 0x10)      && /* T-Clk-Sel */
+        sim->tmr.tick20 != 0
+    ) {
+        tmrUpdate(sim, sim->tmr.counter == 0 ?
+            sim->tmr.reload : sim->tmr.counter - 1);
+    }
+
     /* Parse fields */
     sim->tmr.t_clk_sel = value >> 4 & 1;
     sim->tmr.tim_z_int = value >> 3 & 1;
@@ -105,10 +132,8 @@ static void tmrWriteControl(VB *sim, uint8_t value) {
     if (!sim->tmr.tim_z_int)
         sim->cpu.irq &= ~0x0002;
 
-    /* Configure countdowns */
+    /* Configure state */
-    sim->tmr.clocks = sim->tmr.t_clk_sel ? 400 : 2000;
+    sim->tmr.until = tmrGetUntil(sim);
-    sim->tmr.until  = sim->tmr.clocks * (sim->tmr.counter == 0 ?
-        (uint32_t) sim->tmr.reload + 1 : sim->tmr.counter);
 
     /* TODO: Will Z-Stat raise an interrupt when Tim-Z-Int is set? */
 }
@@ -117,12 +142,14 @@ static void tmrWriteControl(VB *sim, uint8_t value) {
 static void tmrWriteHigh(VB *sim, uint8_t value) {
     sim->tmr.reload = (uint16_t) value << 8 | (sim->tmr.reload & 0x00FF);
     tmrUpdate(sim, sim->tmr.reload);
+    sim->tmr.until  = tmrGetUntil(sim);
 }
 
 /* Write to the low data register */
 static void tmrWriteLow(VB *sim, uint8_t value) {
     sim->tmr.reload = (sim->tmr.reload & 0xFF00) | value;
     tmrUpdate(sim, sim->tmr.reload);
+    sim->tmr.until  = tmrGetUntil(sim);
 }
 
 

core/vb.c

@@ -8,8 +8,11 @@
 
 /*********************************** Types ***********************************/
 
-/* Output image */
+/* VIP BG map cell */
-typedef uint8_t Pixels[2][384*224];
+typedef struct {
+    uint8_t *palette; /* Points to a VB.vip.gplt */
+    uint8_t *pixels;  /* Points to a VB.vip.characters */
+} Cell;
 
 /* VSU channel */
 typedef struct {
@@ -64,9 +67,58 @@ typedef struct {
     } wave;
 
     /* Other state */
-    uint32_t clocks; /* Clocks until next sample */
+    uint32_t clocks;  /* Clocks until next wave or noise sample */
+    uint8_t  freqmod; /* Frequency modifications are active */
+    uint32_t until;   /* Clocks until channel component update */
 } Channel;
 
+/* VIP character (hflp << 1 | vflp) */
+typedef uint8_t Character[4][64];
+
+/* VIP object */
+typedef struct {
+    Cell    cell; /* BG map-like attributes */
+    int16_t jp;   /* Parallax */
+    int16_t jx;   /* Screen base X */
+    int16_t jy;   /* Screen Y */
+    uint8_t lron; /* Visible in left and right images */
+} Object;
+
+/* Output image */
+typedef uint8_t Pixels[2][384*224];
+
+/* VIP world */
+typedef struct {
+
+    /* Attributes */
+    uint8_t  bgm;       /* Mode */
+    uint8_t  end;       /* Control world */
+    int16_t  gp;        /* World parallax */
+    int16_t  gx;        /* World base X */
+    int16_t  gy;        /* World Y */
+    int16_t  mx;        /* Scroll base X */
+    int16_t  mp;        /* Scroll parallax */
+    int16_t  my;        /* Scroll Y */
+    uint8_t  over;      /* Use overplane */
+    Cell    *overplane; /* Overplane cell */
+
+    /* Non-attributes */
+    Cell    *bg[64];    /* Background arrangement */
+    int32_t  bgHeight;  /* Height of background in pixels */
+    uint32_t bgMaskX;   /* Horizontal background mask */
+    uint32_t bgMaskY;   /* Vertical background mask */
+    uint32_t bgShift;   /* Bits to shift when selecting a BG map */
+    int32_t  bgWidth;   /* Width of background in pixels */
+    uint32_t hAffine;   /* H for affine mode */
+    uint32_t hNaffine;  /* H for not affine mode */
+    uint32_t height;    /* Height of world in pixels */
+    uint8_t  lron;      /* Visible in left and right images */
+    uint32_t paramBase; /* H-bias and affine parameter address */
+    uint32_t wAffine;   /* W for affine mode */
+    uint32_t wNaffine;  /* W for not affine mode */
+    uint32_t width;     /* Width of world in pixels */
+} World;
+
 /* Simulation state */
 struct VB {
 
@@ -199,6 +251,7 @@ struct VB {
         uint32_t clocks;  /* Master clocks to wait */
         uint16_t counter; /* Current counter value */
         uint16_t reload;  /* Reload counter value */
+        uint8_t  tick20;  /* Current 20-microsecond tick */
         uint32_t until;   /* Clocks until interrupt condition */
     } tmr;
 
@@ -259,6 +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;
 
@@ -273,12 +327,17 @@ 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 */
 
         /* Other state */
+        Cell      cells[0x10000];   /* Pre-computed BG map attributes */
+        Character characters[2048]; /* Pre-computed character pixels */
+        Object    objects[1024];    /* Pre-computed object attributes */
         uint8_t   ram[0x40000];     /* Video memory */
+        World     worlds[32];       /* Pre-computed world attributes */
     } vip;
 
     /* VSU */
@@ -575,7 +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++;
@@ -643,6 +702,7 @@ VBAPI vbOnWrite vbGetWriteCallback(VB *sim) {
 VBAPI VB* vbInit(VB *sim) {
     sim->cart.ram        = NULL;
     sim->cart.rom        = NULL;
+    sim->ph.enabled      = 0;
     sim->vsu.out.samples = NULL;
     sim->onExecute       = NULL;
     sim->onFetch         = NULL;
@@ -652,7 +712,7 @@ VBAPI VB* vbInit(VB *sim) {
     sim->onSamples       = NULL;
     sim->onWrite         = NULL;
     sim->peer            = NULL;
-    sim->ph.enabled      = 0;
+    sim->tag             = NULL;
     vbReset(sim);
     return sim;
 }
@@ -774,6 +834,8 @@ VBAPI int vbSetOption(VB *sim, int key, int value) {
 VBAPI void vbSetPeer(VB *sim, VB *peer) {
     if (sim->peer == peer)
         return;
+    if (sim->peer != NULL)
+        sim->peer->peer = NULL;
     sim->peer = peer;
     if (peer == NULL)
         return;
@@ -784,6 +846,7 @@ VBAPI void vbSetPeer(VB *sim, VB *peer) {
 
 /* Specify a new value for the program counter */
 VBAPI uint32_t vbSetProgramCounter(VB *sim, uint32_t value) {
+    sim->cpu.clocks    = 0;
     sim->cpu.operation = CPU_FETCH;
     sim->cpu.pc        = sim->cpu.nextPC = value & 0xFFFFFFFE;
     sim->cpu.step      = 0;

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/vsu.c

@@ -74,49 +74,8 @@ static void vsuNextFreqMod(VB *sim, Channel *chan) {
 }
 
 /* Process one channel */
-static void vsuEmulateChannel(VB *sim, int index, uint32_t clocks) {
+static void vsuEmulateChannel(VB *sim, Channel *chan) {
     uint32_t bit; /* Pseudorandom bit */
-    Channel *chan;    /* Channel handle */
-    int      freqmod; /* Frequency modifications enabled */
-    uint32_t until;   /* Clocks to process sub-channel components */
-
-    /* Select channel */
-    chan = &sim->vsu.channels[index];
-
-    /* Channel is disabled */
-    if (!chan->int_.enb)
-        return;
-
-    /* Process all clocks */
-    do {
-
-        /* Frequency modifications are active */
-        freqmod = 
-            index == 4           &&        /* Channel 5 */
-            sim->vsu.freqmod.enb &&        /* Modifications enabled */
-            sim->vsu.freqmod.interval != 0 /* Modifications valid */
-        ;
-
-        /* Clocks until next state change */
-        until = clocks;
-        if (chan->clocks < until)
-            until = chan->clocks;
-        if (chan->env.enb && chan->env.clocks < until)
-            until = chan->env.clocks;
-        if (chan->int_.auto_ && chan->int_.clocks < until)
-            until = chan->int_.clocks;
-        if (freqmod && sim->vsu.freqmod.clocks < until)
-            until = sim->vsu.freqmod.clocks;
-
-        /* Manage clocks */
-        clocks       -= until;
-        chan->clocks -= until;
-        if (chan->env.enb)
-            chan->env.clocks -= until;
-        if (chan->int_.auto_)
-            chan->int_.clocks -= until;
-        if (freqmod)
-            sim->vsu.freqmod.clocks -= until;
 
     /* Automatic shutoff */
     if (chan->int_.auto_ && chan->int_.clocks == 0) {
@@ -124,11 +83,11 @@ static void vsuEmulateChannel(VB *sim, int index, uint32_t clocks) {
         return;
     }
 
-        /* Next sample */
+    /* Next input sample */
     if (chan->clocks == 0) {
 
         /* Wave */
-            if (index != 5) {
+        if (chan != &sim->vsu.channels[5]) {
             chan->clocks =  4 * (2048 - (uint32_t) chan->freq.current);
             chan->wave.sample = (chan->wave.sample + 1) & 31;
         }
@@ -158,7 +117,7 @@ static void vsuEmulateChannel(VB *sim, int index, uint32_t clocks) {
     }
 
     /* Frequency modification */
-        if (freqmod && sim->vsu.freqmod.clocks == 0) {
+    if (chan->freqmod && sim->vsu.freqmod.clocks == 0) {
         chan->freq.current = sim->vsu.freqmod.next;
         vsuNextFreqMod(sim, chan);
         if (!chan->int_.enb)
@@ -167,8 +126,6 @@ static void vsuEmulateChannel(VB *sim, int index, uint32_t clocks) {
             (sim->vsu.freqmod.clk == 0 ? 19200 : 153600);
     }
 
-    } while (clocks != 0);
-
 }
 
 /* Produce output for a channel */
@@ -230,6 +187,8 @@ static void vsuWriteEV1(VB *sim, int index, uint8_t value) {
             sim->vsu.freqmod.func = value >> 4 & 1;
             sim->vsu.freqmod.rep  = value >> 5 & 1;
             vsuNextFreqMod(sim, chan);
+            chan->freqmod =
+                sim->vsu.freqmod.enb && sim->vsu.freqmod.interval != 0;
             break;
 
         case 5: /* Channel 6 */
@@ -313,6 +272,8 @@ static void vsuWriteSWP(VB *sim, uint8_t value) {
         (sim->vsu.freqmod.clk == 0 ? 19200 : 153600);
     if (clocks < sim->vsu.freqmod.clocks)
         sim->vsu.freqmod.clocks = clocks;
+    sim->vsu.channels[4].freqmod =
+        sim->vsu.freqmod.enb && sim->vsu.freqmod.interval != 0;
 }
 
 
@@ -321,6 +282,8 @@ static void vsuWriteSWP(VB *sim, uint8_t value) {
 
 /* Process component */
 static void vsuEmulate(VB *sim, uint32_t clocks) {
+    Channel *chan;      /* Input channel */
+    uint32_t chantil;   /* Clocks until next channel state update */
     float    i0;        /* Current analog input sample */
     float    o0;        /* Current analog output sample */
     uint16_t output[2]; /* Digital output samples */
@@ -340,12 +303,54 @@ static void vsuEmulate(VB *sim, uint32_t clocks) {
         sim->vsu.clocks -= until;
 
         /* Process all channels */
-        for (x = 0; x < 6; x++)
+        for (x = 0; x < 6; x++) {
-            vsuEmulateChannel(sim, x, until);
+            chan    = &sim->vsu.channels[x];
+            chantil = until;
+
+            /* Process all clocks */
+            while (chan->int_.enb && chantil != 0) {
+
+                /* Determine when the next state change will occur */
+                if (chan->until == 0) {
+
+                    /* Clocks until next state change */
+                    chan->until = chan->clocks;
+                    if (chan->env.enb && chan->env.clocks < chan->until)
+                        chan->until = chan->env.clocks;
+                    if (chan->int_.auto_ && chan->int_.clocks < chan->until)
+                        chan->until = chan->int_.clocks;
+                    if (chan->freqmod && sim->vsu.freqmod.clocks < chan->until)
+                        chan->until = sim->vsu.freqmod.clocks;
+
+                    /* Manage clocks */
+                    chan->clocks -= chan->until;
+                    if (chan->env.enb)
+                        chan->env.clocks -= chan->until;
+                    if (chan->int_.auto_)
+                        chan->int_.clocks -= chan->until;
+                    if (chan->freqmod)
+                        sim->vsu.freqmod.clocks -= chan->until;
+                }
+
+                /* Manage clocks */
+                if (chan->until > chantil) {
+                    chan->until -= chantil;
+                    chantil      = 0;
+                } else {
+                    chantil     -= chan->until;
+                    chan->until  = 0;
+                }
+
+                /* Update channel state */
+                if (chan->until == 0)
+                    vsuEmulateChannel(sim, chan);
+            }
+
+        }
 
         /* Wait for the current sample to finish */
         if (sim->vsu.clocks != 0)
-            continue;
+            return;
 
         /* Compute the output sample */
         output[0] = output[1] = 0;
@@ -416,6 +421,8 @@ static void vsuReset(VB *sim) {
     for (x = 0; x < 6; x++) {
         chan = &sim->vsu.channels[x];
         chan->clocks        = 0;
+        chan->freqmod       = 0;
+        chan->until         = 0;
         chan->env.clocks    = 0;
         chan->env.enb       = 0;
         chan->env.dir       = 0;

util/disassembler.c

@@ -1,4 +1,4 @@
-/* This file is included into vb.c and cannot be compiled on its own. */
+/* This file is included into vbu.c and cannot be compiled on its own. */
 #ifdef VBUAPI
 
 
@@ -253,18 +253,24 @@ static void dasmOpDisp26(char*dest, VBU_DasmConfig*config, VBU_DasmLine*line) {
 }
 
 /* Format a 5-bit sign-extended immediate operand */
-static void dasmOpImm5S(char *dest, VBU_DasmLine *line) {
+static void dasmOpImm5S(char *dest, VBU_DasmConfig*config, VBU_DasmLine *line){
+    if (config->immediateNotation == VBU_NUMBER)
+        *dest++ = '#';
     sprintf(dest, "%d", SignExtend(line->code[0], 5));
 }
 
 /* Format a 5-bit zero-filled immediate operand */
-static void dasmOpImm5U(char *dest, VBU_DasmLine *line) {
+static void dasmOpImm5U(char *dest, VBU_DasmConfig*config, VBU_DasmLine *line){
+    if (config->immediateNotation == VBU_NUMBER)
+        *dest++ = '#';
     sprintf(dest, "%d", line->code[0] & 31);
 }
 
 /* Format a 16-bit sign-extended immediate operand */
 static void dasmOpImm16S(char*dest, VBU_DasmConfig*config, VBU_DasmLine*line) {
     int32_t imm    = (int16_t) ((int16_t) line->code[3] << 8 | line->code[2]);
+    if (config->immediateNotation == VBU_NUMBER)
+        *dest++ = '#';
     if (imm >= -256 && imm <= 256) {
         sprintf(dest, "%d", imm);
         return;
@@ -279,6 +285,8 @@ static void dasmOpImm16S(char*dest, VBU_DasmConfig*config, VBU_DasmLine*line) {
 /* Format a 16-bit zero-filled immediate operand */
 static void dasmOpImm16U(char*dest, VBU_DasmConfig*config, VBU_DasmLine*line) {
     uint16_t imm = (uint16_t) line->code[3] << 8 | line->code[2];
+    if (config->immediateNotation == VBU_NUMBER)
+        *dest++ = '#';
     dasmToHex(dest, config, 4, imm);
 }
 
@@ -441,12 +449,6 @@ static VBU_DasmLine* dasmGrow(
     return *lines == NULL ? NULL : &(*lines)[index];
 }
 
-/* Determine the size of an instruction */
-static uint32_t dasmInstSize(VB *sim, uint32_t address) {
-    unsigned opcode = vbRead(sim, address, VB_U16) >> 10 & 63;
-    return opcode < 0x20 || opcode == 0x32 || opcode == 0x36 ? 2 : 4;
-}
-
 /* Format an operand */
 static void dasmOperand(char *dest, VBU_DasmConfig *config,
     VBU_DasmLine *line, uint8_t type) {
@@ -454,8 +456,8 @@ static void dasmOperand(char *dest, VBU_DasmConfig *config,
         case DASM_BCOND : dasmOpBCOND (dest, config, line); break;
         case DASM_DISP9 : dasmOpDisp9 (dest, config, line); break;
         case DASM_DISP26: dasmOpDisp26(dest, config, line); break;
-        case DASM_IMM5S : dasmOpImm5S (dest,         line); break;
+        case DASM_IMM5S : dasmOpImm5S (dest, config, line); break;
-        case DASM_IMM5U : dasmOpImm5U (dest,         line); break;
+        case DASM_IMM5U : dasmOpImm5U (dest, config, line); break;
         case DASM_IMM16S: dasmOpImm16S(dest, config, line); break;
         case DASM_IMM16U: dasmOpImm16U(dest, config, line); break;
         case DASM_JMP   : dasmOpJMP   (dest, config, line); break;
@@ -507,10 +509,12 @@ static int dasmLine(VB *sim, uint32_t *address, uint32_t pc,
     /* Process non-text members */
     line = &(*lines)[index];
     line->address    = *address;
-    line->codeLength = dasmInstSize(sim, *address);
+    line->codeLength = vbuCodeSize(sim, *address);
     line->isPC       = *address == pc;
     for (x = 0; x < line->codeLength; x++)
         line->code[x] = vbRead(sim, *address + x, VB_U8);
+
+    /* Advance to the next instruction or PC, whichever is sooner */
     *address += pc != *address && pc - *address < line->codeLength ?
         pc - *address : line->codeLength;
 
@@ -652,9 +656,11 @@ static VBU_DasmLine* dasmDisassemble(VB *sim, uint32_t address,
         }
 
         /* Check if the instruction contains the reference address */
-        size = dasmInstSize(sim, addr);
+        size = vbuCodeSize(sim, addr);
         if (address - addr < size)
             break;
+
+        /* Advance to the next instruction or PC, whichever is sooner */
         addr += addr != pc && pc - addr < size ? pc - addr : size;
     }
 
@@ -666,7 +672,7 @@ static VBU_DasmLine* dasmDisassemble(VB *sim, uint32_t address,
 
     /* Keep decoding until the first line of output */
     else for (; line < 0; line++)
-        addr += dasmInstSize(sim, addr);
+        addr += vbuCodeSize(sim, addr);
 
     /* Working variables */
     size   = length * sizeof (VBU_DasmLine);
@@ -680,7 +686,7 @@ static VBU_DasmLine* dasmDisassemble(VB *sim, uint32_t address,
         if (dasmLine(sim, &addr, pc, config, &lines, &size, &offset, x))
             goto catch;
     }
-    return lines;
+    return VBU_REALLOC(lines, offset);
 
     /* Exception handler */
     catch:

util/vbu.c

@@ -38,6 +38,12 @@ static int32_t SignExtend(int32_t value, int32_t bits) {
 
 /******************************* API Commands ********************************/
 
+/* Determine the size in bytes of an instruction */
+VBUAPI int vbuCodeSize(VB *sim, uint32_t address) {
+    int opcode = vbRead(sim, address, VB_U16) >> 10 & 63;
+    return opcode < 0x20 || opcode == 0x32 || opcode == 0x36 ? 2 : 4;
+}
+
 /* Initialize disassembler options with default settings */
 VBUAPI VBU_DasmConfig* vbuDasmInit(VBU_DasmConfig *config) {
     config->bcondNotation     = VBU_JOINED;
@@ -47,6 +53,7 @@ VBUAPI VBU_DasmConfig* vbuDasmInit(VBU_DasmConfig *config) {
     config->conditionNotation = VBU_NAMES;
     config->hexCase           = VBU_UPPER;
     config->hexNotation       = VBU_0X;
+    config->immediateNotation = VBU_NONE;
     config->memoryNotation    = VBU_OUTSIDE;
     config->mnemonicCase      = VBU_UPPER;
     config->operandOrder      = VBU_DEST_LAST;

util/vbu.h

@@ -29,6 +29,8 @@ extern "C" {
 #define VBU_L          0
 #define VBU_LOWER      1
 #define VBU_NAMES      1
+#define VBU_NONE       0
+#define VBU_NUMBER     1
 #define VBU_NUMBERS    0
 #define VBU_OUTSIDE    0
 #define VBU_SPLIT      1
@@ -48,6 +50,7 @@ typedef struct {               /* Defaults listed first */
     uint8_t conditionNotation; /* NAMES, NUMBERS */
     uint8_t hexCase;           /* UPPER, LOWER */
     uint8_t hexNotation;       /* 0X, H, DOLLAR */
+    uint8_t immediateNotation; /* NONE, NUMBER */
     uint8_t memoryNotation;    /* OUTSIDE, INSIDE */
     uint8_t mnemonicCase;      /* UPPER, LOWER */
     uint8_t operandOrder;      /* DEST_LAST, DEST_FIRST */
@@ -82,6 +85,7 @@ typedef struct {
 
 /******************************* API Commands ********************************/
 
+VBUAPI int             vbuCodeSize   (VB *sim, uint32_t address);
 VBUAPI VBU_DasmConfig* vbuDasmInit   (VBU_DasmConfig *config);
 VBUAPI VBU_DasmLine*   vbuDisassemble(VB *sim, uint32_t address, VBU_DasmConfig *config, unsigned length, int line);
 

web/Constants.js

@@ -61,6 +61,8 @@ let Constants = {
         L         : 0,
         LOWER     : 1,
         NAMES     : 1,
+        NONE      : 0,
+        NUMBER    : 1,
         NUMBERS   : 0,
         OUTSIDE   : 0,
         SPLIT     : 1,

web/Core.js

@@ -87,10 +87,7 @@ new class Core {
             this.sims.set(sim.pointer, sim);
 
             // Video
-            sim.pixels = this.#noalloc(
+            sim.pixels = this.#getPixels(sim);
-                this.GetExtPixels(sim.pointer),
-                384*224*4, sim, "pixels", Uint8ClampedArray
-            );
             sim.image  = new ImageData(sim.pixels, 384, 224);
 
             // Audio
@@ -128,6 +125,7 @@ new class Core {
                 message.config.conditionNotation,
                 message.config.hexCase,
                 message.config.hexNotation,
+                message.config.immediateNotation,
                 message.config.memoryNotation,
                 message.config.mnemonicCase,
                 message.config.operandOrder,
@@ -363,9 +361,11 @@ new class Core {
             this.mallocs.set(buffer.pointer, buffer);
             this.#updateTarget(buffer);
         }
-        for (let sim of this.sims)
+        for (let sim of this.sims.values()) {
+            sim.pixels = this.#getPixels(sim);
             sim.image  = new ImageData(sim.pixels, 384, 224);
         }
+    }
 
 
 
@@ -435,6 +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(

web/VB.js

@@ -19,6 +19,7 @@ class DasmConfig {
     #conditionNotation;
     #hexCase;
     #hexNotation;
+    #immediateNotation;
     #memoryNotation;
     #mnemonicCase;
     #operandOrder;
@@ -40,6 +41,7 @@ class DasmConfig {
         this.#conditionNotation = Constants.VBU.NAMES;
         this.#hexCase           = Constants.VBU.UPPER;
         this.#hexNotation       = Constants.VBU["0X"];
+        this.#immediateNotation = Constants.VBU.NONE;
         this.#memoryNotation    = Constants.VBU.OUTSIDE;
         this.#mnemonicCase      = Constants.VBU.UPPER;
         this.#operandOrder      = Constants.VBU.DEST_LAST;
@@ -125,6 +127,16 @@ class DasmConfig {
         this.#hexNotation = value;
     }
 
+    get immediateNotation() { return this.#immediateNotation; }
+    set immediateNotation(value) {
+        switch (value) {
+            case Constants.VBU.NONE  :
+            case Constants.VBU.NUMBER: break;
+            default: return;
+        }
+        this.#immediateNotation = value;
+    }
+
     get memoryNotation() { return this.#memoryNotation; }
     set memoryNotation(value) {
         switch (value) {
@@ -407,6 +419,7 @@ class Sim extends HTMLElement {
                 conditionNotation: config.conditionNotation,
                 hexCase          : config.hexCase,
                 hexNotation      : config.hexNotation,
+                immediateNotation: config.immediateNotation,
                 memoryNotation   : config.memoryNotation,
                 mnemonicCase     : config.mnemonicCase,
                 operandOrder     : config.operandOrder,
@@ -650,6 +663,8 @@ class VB {
     static get L         () { return Constants.VBU.L         ; }
     static get LOWER     () { return Constants.VBU.LOWER     ; }
     static get NAMES     () { return Constants.VBU.NAMES     ; }
+    static get NONE      () { return Constants.VBU.NONE      ; }
+    static get NUMBER    () { return Constants.VBU.NUMBER    ; }
     static get NUMBERS   () { return Constants.VBU.NUMBERS   ; }
     static get OUTSIDE   () { return Constants.VBU.OUTSIDE   ; }
     static get RELATIVE  () { return Constants.VBU.RELATIVE  ; }

web/wasm.c

@@ -108,9 +108,9 @@ EMSCRIPTEN_KEEPALIVE void* CreateSim() {
 // Disassemble from a simulation
 EMSCRIPTEN_KEEPALIVE void* Disassemble(
     int bcondNotation, int conditionCase, int conditionCL, int conditionEZ,
-    int conditionNotation, int hexCase, int hexNotation, int memoryNotation,
+    int conditionNotation, int hexCase, int hexNotation, int immediateNotation,
-    int mnemonicCase, int operandOrder, int programCase, int programNotation,
+    int memoryNotation, int mnemonicCase, int operandOrder, int programCase,
-    int setfNotation, int systemCase, int systemNotation,
+    int programNotation, int setfNotation, int systemCase, int systemNotation,
     VB *sim, uint32_t address, unsigned length, int line
 ) {
     VBU_DasmConfig config;
@@ -121,6 +121,7 @@ EMSCRIPTEN_KEEPALIVE void* Disassemble(
     config.conditionNotation = conditionNotation;
     config.hexCase           = hexCase;
     config.hexNotation       = hexNotation;
+    config.immediateNotation = immediateNotation;
     config.memoryNotation    = memoryNotation;
     config.mnemonicCase      = mnemonicCase;
     config.operandOrder      = operandOrder;