A little more meat on the X86FPU bones

modules/pcjs/lib/chipset.js

@@ -1129,7 +1129,7 @@ ChipSet.prototype.powerUp = function(data, fRepower)
  */
 ChipSet.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/cpu.js

@@ -301,7 +301,7 @@ CPU.prototype.powerDown = function(fSave, fShutdown)
      *
      *      this.aFlags.fPowered = false;
      */
-    return fSave && this.save ? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/debugger.js

@@ -432,6 +432,8 @@ if (DEBUGGER) {
         "FINCSTP","FDECSTP","FFREE",  "FNOP",   "FWAIT"
     ];
 
+    Debugger.FPU_TAGS = ["VALID", "ZERO", "SPECIAL", "EMPTY"];
+
     Debugger.CPU_8086  = 0;
     Debugger.CPU_80186 = 1;
     Debugger.CPU_80286 = 2;
@@ -1404,6 +1406,7 @@ if (DEBUGGER) {
         this.cmp = cmp;
         this.fdc = cmp.getMachineComponent("FDC");
         this.hdc = cmp.getMachineComponent("HDC");
+        this.fpu = cmp.getMachineComponent("FPU");
         this.mouse = cmp.getMachineComponent("Mouse");
         if (MAXDEBUG) this.chipset = cmp.getMachineComponent("ChipSet");
 
@@ -3962,7 +3965,7 @@ if (DEBUGGER) {
     Debugger.prototype.powerDown = function(fSave, fShutdown)
     {
         if (fShutdown) this.println(fSave? "suspending" : "shutting down");
-        return fSave && this.save? this.save() : true;
+        return fSave? this.save() : true;
     };
 
     /**
@@ -4904,14 +4907,15 @@ if (DEBUGGER) {
         var r_m = (bModRM & 0x7);
 
         /*
-         * Similar to how fnFPU() decodes FPU instructions, we combine mod and reg into one
+         * Similar to how opFPU() decodes FPU instructions, we combine mod and reg into one
          * decodable value: put mod in the high nibble and reg in the low nibble, after first
          * collapsing all mod values < 3 to zero.
          */
         var modReg = (mod < 3? 0 : 0x30) + reg;
 
         /*
-         * Use values >= 0x40 to indicate mod == 0x3, with reg in the high nibble and r_m in the low.
+         * All values >= 0x34 imply mod == 3 and reg >= 4, so now we shift reg into the high
+         * nibble and r_m into the low.
          */
         if ((bOpcode == X86.OPCODE.ESC1 || bOpcode == X86.OPCODE.ESC3) && modReg >= 0x34) {
             modReg = (reg << 4) | r_m;
@@ -7021,6 +7025,7 @@ if (DEBUGGER) {
         if (asArgs && asArgs[1] == '?') {
             this.println("register commands:");
             this.println("\tr\tdump registers");
+            if (this.fpu) this.println("\trfp\tdump floating-point registers");
             this.println("\trp\tdump all registers");
             this.println("\trx [#]\tset flag or register x to [#]");
             return;
@@ -7031,9 +7036,14 @@ if (DEBUGGER) {
 
         if (asArgs != null && asArgs.length > 1) {
             var sReg = asArgs[1];
+            if (this.fpu && sReg == "fp") {
+                this.doFPURegisters(asArgs);
+                return;
+            }
             if (sReg == 'p') {
                 fProt = (this.cpu.model >= X86.MODEL_80286);
-            } else {
+            }
+            else {
              // fInstruction = false;
                 var sValue = null;
                 var i = sReg.indexOf('=');
@@ -7269,6 +7279,26 @@ if (DEBUGGER) {
         }
     };
 
+    /**
+     * doFPURegisters(asArgs)
+     *
+     * NOTE: If we're called, the existence of an FPU has already been verified.
+     *
+     * @this {Debugger}
+     * @param {Array.<string>} [asArgs]
+     */
+    Debugger.prototype.doFPURegisters = function(asArgs)
+    {
+        this.assert(this.fpu);
+        for (var i = 0; i < 8; i++) {
+            var a = this.fpu.readFPUStack(i);
+            if (!a) break;
+            var sValue = str.pad(a[2].toFixed(15), 24, true);
+            this.println("ST" + i + ": " + sValue + "  " + str.toHex(a[4]) + "," + str.toHex(a[3]) + "  [" + Debugger.FPU_TAGS[a[1]] + "]");
+            // this.println("  REG" + a[0] + " " + str.toBin(a[7], 16) + str.toBin(a[6]) + str.toBin(a[5]));
+        }
+    };
+
     /**
      * doRun(sCmd, sAddr, sOptions, fQuiet)
      *

modules/pcjs/lib/fdc.js

@@ -614,7 +614,7 @@ FDC.prototype.powerUp = function(data, fRepower)
  */
 FDC.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/hdc.js

@@ -572,7 +572,7 @@ HDC.prototype.powerUp = function(data, fRepower)
  */
 HDC.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/keyboard.js

@@ -1373,7 +1373,7 @@ Keyboard.prototype.powerUp = function(data, fRepower)
  */
 Keyboard.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/mouse.js

@@ -294,7 +294,7 @@ Mouse.prototype.powerUp = function(data, fRepower)
  */
 Mouse.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/serialport.js

@@ -444,7 +444,7 @@ SerialPort.prototype.powerUp = function(data, fRepower)
  */
 SerialPort.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save ? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/video.js

@@ -3497,7 +3497,7 @@ Video.prototype.powerUp = function(data, fRepower)
  */
 Video.prototype.powerDown = function(fSave, fShutdown)
 {
-    return fSave && this.save? this.save() : true;
+    return fSave? this.save() : true;
 };
 
 /**

modules/pcjs/lib/x86.js

@@ -524,6 +524,7 @@ var X86 = {
     FPU: {
         MODEL_8087:     8087,
         MODEL_80287:    80287,
+        MODEL_80287XL:  80387,  // internally, the 80287XL was an 80387SX, so I'm not sure we really want/need a unique identifier
         MODEL_80387:    80387,
         CONTROL: {              // FPU Control Word
             IM:     0x0001,     // bit 0: Invalid Operation Mask
@@ -532,13 +533,15 @@ var X86 = {
             OM:     0x0008,     // bit 3: Overflow Mask
             UM:     0x0010,     // bit 4: Underflow Mask
             PM:     0x0020,     // bit 5: Precision Mask
+            EXC:    0x003F,     // all of the above exceptions
                                 // bit 6: unused
             IEM:    0x0080,     // bit 7: Interrupt Enable Mask (0 enables interrupts, 1 masks them; 8087 only)
             PC:     0x0300,     // bits 8-9: Precision Control
             RC:     0x0C00,     // bits 10-11: Rounding Control
             IC:     0x1000,     // bit 12: Infinity Control (0 for Projective, 1 for Affine)
                                 // bits 13-15: unused
-            INIT:   0x03BF      // X86.FPU.CONTROL.IM | X86.FPU.CONTROL.DM | X86.FPU.CONTROL.ZM | X86.FPU.CONTROL.OM | X86.FPU.CONTROL.UM | X86.FPU.CONTROL.PM | X86.FPU.CONTROL.IEM | X86.FPU.CONTROL.PC
+            INIT:   0x03BF,     // X86.FPU.CONTROL.IM | X86.FPU.CONTROL.DM | X86.FPU.CONTROL.ZM | X86.FPU.CONTROL.OM | X86.FPU.CONTROL.UM | X86.FPU.CONTROL.PM | X86.FPU.CONTROL.IEM | X86.FPU.CONTROL.PC
+            UNUSED: 0xE040
         },
         STATUS: {               // FPU Status Word
             IE:     0x0001,     // bit 0: Invalid Operation
@@ -555,7 +558,8 @@ var X86 = {
             C2:     0x0400,     // bit 10: Condition Code 2
             ST:     0x3800,     // bits 11-13: Stack Top
             C3:     0x4000,     // bit 14: Condition Code 3
-            BUSY:   0x8000      // bit 15: Busy
+            BUSY:   0x8000,     // bit 15: Busy
+            ST_SHIFT: 11
         },
         TAGS: {
             VALID:  0x0,

modules/pcjs/lib/x86cpu.js

@@ -1186,6 +1186,8 @@ X86CPU.prototype.resetRegs = function()
     this.opFlags = this.opPrefixes = 0;
     this.regEA = this.regEAWrite = X86.ADDR_INVALID;
 
+    this.segEA = this.segNULL;
+
     /*
      * intFlags contains some internal states we use to indicate whether a hardware interrupt (INTFLAG.INTR) or
      * Trap software interrupt (INTR.TRAP) has been requested, as well as when we're in a "HLT" state (INTFLAG.HALT)

modules/pcjs/lib/x86seg.js

@@ -142,7 +142,8 @@ X86Seg.ID = {
     TSS:    4,          // "TSS"
     LDT:    5,          // "LDT"
     VER:    6,          // "VER"
-    DBG:    7           // "DBG"
+    FPU:    7,          // "FPU"
+    DBG:    8           // "DBG"
 };
 
 X86Seg.CALLBREAK_SEL = 0x0001;

modules/shared/lib/strlib.js

@@ -375,17 +375,19 @@ str.replaceArray = function(a, s)
 };
 
 /**
- * pad(s, cch)
+ * pad(s, cch, fPadLeft)
  *
  * NOTE: the maximum amount of padding currently supported is 40 spaces.
  *
  * @param {string} s is a string
  * @param {number} cch is desired length
+ * @param {boolean} [fPadLeft] (default is padding on the right)
  * @returns {string} the original string (s) with spaces padding it to the specified length
  */
-str.pad = function(s, cch)
+str.pad = function(s, cch, fPadLeft)
 {
-    return s + "                                        ".substr(0, cch - s.length);
+    var sPadding = "                                        ";
+    return fPadLeft? (sPadding + s).slice(-cch) : (s + sPadding).slice(0, cch);
 };
 
 /**