Memory class is now being treated as an interface. Bank takes the place of Memory and Bank extends Memory. MMC also extends Memory.

src/bank.js

@@ -0,0 +1,60 @@
+
+var Memory = require('src/memory');
+
+class Bank extends Memory{
+  constructor(size, ro){
+    super();
+    this.__ro = (ro === true);
+    this.__map = null;
+    this.__addr = 0;
+    if (size > 0){
+      this.__map = new Uint8Array(size);
+    }
+    this.__listeners = {};
+  }
+
+  get size(){return (this.__map) ? this.__map.length : 0;}
+
+  get address(){return this.__addr;}
+  set address(a){
+    if (this.__map)
+      this.__addr = Math.min(this.__map.length, Math.max(0, a));
+  }
+
+  get byte(){return (this.__map) ? this.__map[this.__addr] : -1;}
+  set byte(b){
+    if (!this.__ro && this.__map){
+      this.__map[this.__addr] = b;
+      if (this.__addr in this.__listeners)
+        this.__listeners[this.__addr].forEach((fn)=>{fn(b);});
+    }
+  }
+
+  onAddressWrite(addr, fn){
+    if (addr < 0 || addr >= this.size)
+      throw new RangeError("Memory address is out of bounds.");
+    if (typeof(fn) !== 'function')
+      throw new TypeErrpr("Expected a callback function.");
+    if (!(addr in this.__listeners))
+      this.__listeners[addr] = [];
+    // WARNING: Not testing to see if using the same function more than once.
+    this.__listeners[addr].push(fn);
+  }
+
+  // This method is intended for the emulator to fill a Read-Only memory module with data prior to
+  // the start of execution. This method should never be used in a running system.
+  sysStore(address, data){
+    if (this.__map){
+      let dc = data;
+      if (address < 0 || address >= this.__map.length)
+        throw new RangeError("Memory address out of range.");
+      if (this.__map.length - address < dc.length)
+        dc = dc.slice(0, this.__map.length - address);
+      this.__map.set(address, dc);
+      return dc.length;
+    }
+  }
+}
+
+
+module.exports = Bank;

src/memory.js

@@ -1,57 +1,15 @@
 
 
 class Memory{
-  constructor(size, ro){
-    this.__ro = (ro === true);
-    this.__map = null;
-    this.__addr = 0;
-    if (size > 0){
-      this.__map = new Uint8Array(size);
-    }
-    this.__listeners = {};
-  }
+  constructor(){}
 
-  get size(){return (this.__map) ? this.__map.length : 0;}
+  get size(){return 0;}
 
-  get address(){return this.__addr;}
-  set address(a){
-    if (this.__map)
-      this.__addr = Math.min(this.__map.length, Math.max(0, a));
-  }
+  get address(){return 0;}
+  set address(a){}
 
-  get byte(){return (this.__map) ? this.__map[this.__addr] : -1;}
-  set byte(b){
-    if (!this.__ro && this.__map){
-      this.__map[this.__addr] = b;
-      if (this.__addr in this.__listeners)
-        this.__listeners[this.__addr].forEach((fn)=>{fn(b);});
-    }
-  }
-
-  onAddressWrite(addr, fn){
-    if (addr < 0 || addr >= this.size)
-      throw new RangeError("Memory address is out of bounds.");
-    if (typeof(fn) !== 'function')
-      throw new TypeErrpr("Expected a callback function.");
-    if (!(addr in this.__listeners))
-      this.__listeners[addr] = [];
-    // WARNING: Not testing to see if using the same function more than once.
-    this.__listeners[addr].push(fn);
-  }
-
-  // This method is intended for the emulator to fill a Read-Only memory module with data prior to
-  // the start of execution. This method should never be used in a running system.
-  sysStore(address, data){
-    if (this.__map){
-      let dc = data;
-      if (address < 0 || address >= this.__map.length)
-        throw new RangeError("Memory address out of range.");
-      if (this.__map.length - address < dc.length)
-        dc = dc.slice(0, this.__map.length - address);
-      this.__map.set(address, dc);
-      return dc.length;
-    }
-  }
+  get byte(){return -1;}
+  set byte(b){}
 }
 
 

src/mmc.js

@@ -1,7 +1,7 @@
 
-var Memory = require('chip/memory');
+var Memory = require('src/memory');
 
-class Bank{
+class Switch{
   constructor(mem){
     this.__mem = [mem];
     this.__idx = 0;
@@ -28,60 +28,61 @@ class Bank{
 
 
 
-class MMC{
+class MMC extends Memory{
   constructor(){
-    this.__banks = [];
+    super();
+    this.__switches = [];
     this.__addr = 0;
-    this.__bnkidx = 0;
+    this.__sidx = 0;
   }
 
   get size(){
-    return this.__banks.reduce((acc, b)=>{
-      acc += b.mem.size;
+    return this.__switches.reduce((acc, s)=>{
+      acc += s.mem.size;
     }, 0);
   }
 
-  get banks(){return this.__banks.length;}
+  get switches(){return this.__switches.length;}
 
   get address(){return this.__addr;}
   set address(a){
     if (a >= 0 && a < this.size){
       this.__addr = a;
       offset = 0;
-      for (let b=0; b < this.__banks.length; b++){
-        if (a >= offset && a < offset + this.__banks[b].mem.size){
-          this.__bnkidx = b;
-          this.__banks[b].mem.address = a - offset;
+      for (let s=0; s < this.__switches.length; s++){
+        if (a >= offset && a < offset + this.__switches[s].mem.size){
+          this.__sidx = b;
+          this.__switches[s].mem.address = a - offset;
           break;
         } else {
-          offset += this.__banks[b].mem.size;
+          offset += this.__switches[s].mem.size;
         }
       }
     }
   }
 
-  get byte(){return (this.__banks.length > 0) ? this.__banks[this.__bnkidx].mem.byte : -1;}
+  get byte(){return (this.__switches.length > 0) ? this.__switches[this.__sidx].mem.byte : -1;}
   set byte(b){
-    if (this.__banks.length > 0){
-      this.__banks[this.__bnkidx].mem.byte = b;
+    if (this.__switches.length > 0){
+      this.__switches[this.__sidx].mem.byte = b;
     }
   }
 
   connectMemory(mem, addroff){
     addroff = (typeof(addroff) === 'number' && addroff >= 0) ? addroff : -1;
     if (addroff < 0 || addroff === this.size){
-      this.__banks.push(new Bank(mem));
+      this.__switches.push(new Switch(mem));
     } else {
       offset = 0;
-      for (let b=0; b < this.__banks.length; b++){
+      for (let s=0; s < this.__switches.length; s++){
         if (addroff === offset){
-          if (this.__banks[b].mem.size !== mem.size)
+          if (this.__switches[s].mem.size !== mem.size)
             throw new RangeError("Memory modules assigned to the same bank must be the same byte size.");
-          this.__banks[b].addMemModule(mem);
+          this.__switches[s].addMemModule(mem);
           offset = -1;
           break;
         } else {
-          offset += this.__banks[b].mem.size;
+          offset += this.__switches[s].mem.size;
         }
       }
       if (offset >= 0)
@@ -93,8 +94,8 @@ class MMC{
   mmSwitchRegister(){
     return (function(byte){
       let mmcidx = (byte & 0xF0) >> 4;
-      if (mmcidx < this.__banks.length){
-        this.__banks[mmcidx].idx = (byte & 0x0F);
+      if (mmcidx < this.__switches.length){
+        this.__switches[mmcidx].idx = (byte & 0x0F);
       }
     }).bind(this);
   }