diff --git a/modules/pcjs/lib/bus.js b/modules/pcjs/lib/bus.js
index 185673da5..b780bef7c 100644
--- a/modules/pcjs/lib/bus.js
+++ b/modules/pcjs/lib/bus.js
@@ -58,10 +58,9 @@ if (typeof module !== 'undefined') {
  * addMemory().  If the component needs something more than simple read/write storage,
  * it must provide a controller with getMemoryBuffer() and getMemoryAccess() methods.
  *
- * By contrast, all port access operations are defined by external handlers; they
- * register with us, and we manage those registrations, and we'll probably provide I/O
- * breakpoints at some point, but unlike memory accesses, we're not involved with I/O
- * accesses at all.
+ * By contrast, all port (I/O) operations are defined by external handlers; they register
+ * with us, and we manage those registrations, as well as support for I/O breakpoints,
+ * but unlike memory accesses, we're not involved with port data accesses.
  *
  * @constructor
  * @extends Component
diff --git a/modules/pcjs/lib/chipset.js b/modules/pcjs/lib/chipset.js
index 5a122006d..6a4c57c5e 100644
--- a/modules/pcjs/lib/chipset.js
+++ b/modules/pcjs/lib/chipset.js
@@ -663,7 +663,7 @@ ChipSet.PPI_SW = {
  * documents in /devices/pc/keyboard, as well as the following websites:
  *
  *      http://halicery.com/8042/8042_INTERN_TXT.htm
- *      http://www.os2museum.com/wp/?p=589 ("IBM PC/AT 8042 Keyboard Controller Commands")
+ *      http://www.os2museum.com/wp/ibm-pcat-8042-keyboard-controller-commands/
  */
 ChipSet.KBC = {
     DATA: {                     // this.b8042OutBuff (PPI_A on previous models, still referred to as "PORT A" by the MODEL_5170 BIOS)
@@ -4844,6 +4844,8 @@ ChipSet.prototype.messageBitsIRQ = function(nIRQ)
         bitsMessage |= Messages.KEYBOARD;
     } else if (nIRQ == ChipSet.IRQ.SLAVE) {     // IRQ 2 (MODEL_5170 and up)
         bitsMessage |= Messages.CHIPSET;
+    } else if (nIRQ == ChipSet.IRQ.COM1 || nIRQ == ChipSet.IRQ.COM2) {
+        bitsMessage |= Messages.SERIAL;
     } else if (nIRQ == ChipSet.IRQ.XTC) {       // IRQ 5 (MODEL_5160)
         bitsMessage |= Messages.HDC;
     } else if (nIRQ == ChipSet.IRQ.FDC) {       // IRQ 6
diff --git a/modules/pcjs/lib/defines.js b/modules/pcjs/lib/defines.js
index 144a26fa6..6a0837cca 100644
--- a/modules/pcjs/lib/defines.js
+++ b/modules/pcjs/lib/defines.js
@@ -98,7 +98,7 @@ var FATARRAYS = false;
  * TYPEDARRAYS enables use of typed arrays for Memory blocks.  This used to be a compile-time-only option, but I've
  * added Memory access functions for typed arrays (see Memory.afnTypedArray), so support can be enabled dynamically.
  *
- * However, TYPEDARRAYS has always been slightly slower than the original DWORDARRAYS implementation (which uses an
+ * However, TYPEDARRAYS has always been slightly slower than the original NUMARRAYS implementation (which uses an
  * Array of numbers that stores 32 bits -- 4 consecutive bytes -- per number), so TYPEDARRAYS is completely disabled.
  *
  * See the Memory component for details.
diff --git a/modules/pcjs/lib/mem.js b/modules/pcjs/lib/mem.js
index 163f8f5af..862340930 100644
--- a/modules/pcjs/lib/mem.js
+++ b/modules/pcjs/lib/mem.js
@@ -80,17 +80,20 @@ if (typeof module !== 'undefined') {
  * Because Memory blocks now allow us to have a "sparse" address space, we could choose to
  * take the memory hit of allocating 4K arrays per block, where each element stores only one byte,
  * instead of the more frugal but slightly slower approach of allocating arrays of 32-bit dwords
- * (DWORDARRAYS) and shifting/masking bytes/words to/from dwords; in theory, byte accesses would
+ * (NUMARRAYS) and shifting/masking bytes/words to/from dwords; in theory, byte accesses would
  * be faster and word accesses somewhat less faster.
  *
  * However, preliminary testing of that feature (FATARRAYS) did not yield significantly faster
- * performance, so it is OFF by default to minimize our memory consumption.  Using TYPEDARRAYS is
- * probably best, although not all JavaScript implementations support them (IE9 is probably the
- * only real outlier: it lacks typed arrays but otherwise has all the necessary HTML5 support).
+ * performance, so it is OFF by default to minimize our memory consumption.  Using TYPEDARRAYS
+ * would seem best, but as discussed in defines.js, it's off by default, because it doesn't perform
+ * as well as NUMARRAYS; the other advantage of TYPEDARRAYS is that it should theoretically use
+ * about 1/2 the memory of NUMARRAYS (32-bit elements vs 64-bit numbers), but I value speed over size
+ * at this point.  Also, not all JavaScript implementations support TYPEDARRAYS (IE9 is probably
+ * the only real outlier: it lacks typed arrays but otherwise has all the necessary HTML5 support).
  *
- * WARNING: Since Memory blocks are low-level objects that have no UI requirements,
- * they do not inherit from the Component class, so you should only use class methods
- * of Component, such as Component.assert(), or Debugger methods if the Debugger is available.
+ * WARNING: Since Memory blocks are low-level objects that have no UI requirements, they
+ * do not inherit from the Component class, so you should only use class methods of Component,
+ * such as Component.assert(), or Debugger methods if a debugger (dbg) is available.
  *
  * @constructor
  * @param {number} addr of block (must be some multiple of bus.blockSize)
diff --git a/modules/shared/lib/component.js b/modules/shared/lib/component.js
index 626ea07a8..7e457162b 100644
--- a/modules/shared/lib/component.js
+++ b/modules/shared/lib/component.js
@@ -43,9 +43,8 @@
  *
  * I wasn't thrilled about replacing all "++" and "--" operators with "+= 1" and "-= 1", nor about using
  * "(s || '')" instead of "(s? s : '')", because while the former may seem simpler, it is NOT more portable.
- * It's not that I'm trying to write "portable JavaScript", but some of this code was ported from C code
- * I'd written about 14 years earlier, and portability is good, so I see no reason to rewrite code to make
- * it less portable.
+ * It's not that I'm trying to write "portable JavaScript", but some of this code was ported from C code I'd
+ * written about 14 years earlier, and portability is good, so I'm not going to rewrite if there's no need.
  *
  * UPDATE: I've since switched to JSHint, which seems to have more reasonable defaults.
  */
@@ -228,7 +227,7 @@ Component.add = function(component)
     /*
      * This just generates a lot of useless noise, handy in the early days, not so much these days...
      *
-     *      Component.log("Component.add(" + component.type + "," + component.id + ")");
+     *      if (DEBUG) Component.log("Component.add(" + component.type + "," + component.id + ")");
      */
     Component.all[Component.all.length] = component;
 };
@@ -406,7 +405,7 @@ Component.getComponentByID = function(id, idRelated)
                 return Component.all[i];
             }
         }
-        Component.log('Component.getComponentByID("' + id + '"): no component found', "warning");
+        Component.log("Component ID '" + id + "' not found", "warning");
     }
     return null;
 };
@@ -444,7 +443,7 @@ Component.getComponentByType = function(sType, idRelated, componentPrev)
                 return Component.all[i];
             }
         }
-        Component.log('Component.getComponentByType("' + sType + '"): no component found', "warning");
+        Component.log("Component type '" + sType + "' not found", "warning");
     }
     return null;
 };
@@ -532,12 +531,12 @@ Component.bindComponentControls = function(component, element, sAppClass)
                         if (parms && parms['binding']) {
                             component.setBinding(parms['type'], parms['binding'], control);
                         } else {
-                            Component.log('Component.bindComponentControls("' + component.toString() + '"): missing binding' + (parms? ' for ' + parms['type'] : ''), "warning");
+                            Component.log("Component '" + component.toString() + "' missing binding" + (parms? " for " + parms['type'] : ""), "warning");
                         }
                         iClass = aClasses.length;
                         break;
                     default:
-                        // Component.log("Component.bindComponentControls(" + component.toString() + "): unrecognized control class \"" + sClass + "\"", "warning");
+                        // if (DEBUG) Component.log("Component.bindComponentControls(" + component.toString() + "): unrecognized control class \"" + sClass + "\"", "warning");
                         break;
                 }
             }
@@ -577,7 +576,7 @@ Component.getElementsByClass = function(element, sClass, sObjClass)
         }
     }
     if (!ae.length) {
-        Component.log('no elements of class "' + sClass + '" found');
+        Component.log('No elements of class "' + sClass + '" found');
     }
     return ae;
 };