Fixed an old annoying bug where a restored video card wouldn't properly display a blinking cursor; originally, I assumed it was a CRTC register restoration bug, but actually, some supporting variables (eg, cBlinks) were not getting initialized in both the reset() and restore() code paths. This is also a good time to remember that when an uninitialized array from some hardware state gets serialized and deserialized to/from JSON, the array is restored as a series of "null" values, not as "undefined" values, so it's best for any code checking for undefined values to use "== null" rather than "=== undefined".

README.md

@@ -1,3 +1,17 @@
+---
+layout: page
+permalink: /
+machines:
+  - id: ibm5150
+    type: pcx86
+    resume: 1
+    name: "IBM PC (Model 5150) with Monochrome Display"
+    config: /devices/pcx86/machine/5150/mda/64kb/machine.xml
+  - id: demoC1P
+    type: c1p
+    config: /devices/c1p/machine/8kb/large/machine.xml
+---
+
 PCjs Machines
 =============
 
@@ -14,7 +28,7 @@ All PCjs machine simulations are written entirely in [JavaScript](/modules/).  N
 required.  Supported browsers include modern versions of Chrome, Safari, Firefox, Internet Explorer (v9.0 and up), Edge,
 and assorted mobile browsers.
 
-[Embedded IBM PC](/devices/pcx86/machine/5150/mda/64kb/ "PCx86:ibm5150")
+{% include machine.html id="ibm5150" %}
 
 The [JavaScript Machine](/devices/pcx86/machine/5150/mda/64kb/) above uses [PCx86](/docs/pcx86/) configured with an Intel
 8088 running at 4.77Mhz, with 64Kb of RAM and an IBM Monochrome Display Adapter.  For more control, there are also
@@ -62,7 +76,7 @@ Below is the [OSI Challenger C1P](/docs/c1pjs/), another simulation in the PCjs
 It simulates Ohio Scientific's 6502-based microcomputer, released in 1978.  More details about this simulation
 and the original machine are available in the [C1Pjs Documentation](/docs/c1pjs/).
 
-[Embedded OSI Challenger C1P](/devices/c1p/machine/8kb/large/ "C1Pjs:demoC1P")
+{% include machine.html id="demoC1P" %}
 
 <!--BEGIN:EXCLUDE-->
 

modules/pcx86/lib/bus.js

@@ -1308,7 +1308,7 @@ class Bus extends Component {
             if (aNotify !== undefined) {
                 if (aNotify[0]) {
                     dataPort = aNotify[0](port, addrLIP);
-                    if (dataPort === undefined) {
+                    if (dataPort == null) {
                         dataPort = maskPort;
                     } else {
                         dataPort &= maskPort;

modules/pcx86/lib/video.js

@@ -3166,10 +3166,6 @@ class Video extends Component {
         this.buildFonts();
 
         this.nMode = null;
-        this.iCellCursor = -1;  // initially, there is no visible cursor cell
-        this.cBlinks = -1;      // initially, blinking is not active
-        this.cBlinkVisible = 0; // no visible blinking characters (yet)
-
         this.setMode(this.nModeDefault);
 
         if (this.cardActive.addrBuffer && fRandomize) {
@@ -3697,6 +3693,14 @@ class Video extends Component {
                 }
             }
         }
+        if (!fRebuild) {
+            /*
+             * Perform some additional initialization common to both reset() and restore() sequences.
+             */
+            this.iCellCursor = -1;  // initially, there is no visible cursor cell
+            this.cBlinks = -1;      // initially, blinking is not active
+            this.cBlinkVisible = 0; // no visible blinking characters (yet)
+        }
         return fChanges;
     }
 
@@ -6399,7 +6403,7 @@ class Video extends Component {
          * The IBM VGA ROM makes some hardware determinations based on how the CRTC controller responds when
          * the IO_SELECT bit in the Miscellaneous Output Register is cleared; normally, that would mean ports
          * 0x3B? are decoded and ports 0x3D? are ignored.  We didn't used to bother ignoring them, but the
-         * VGA ROM's logic requires it, so now we also check fActive.  However, we ignore only CTRC reads;
+         * VGA ROM's logic requires it, so now we also check fActive.  However, we ignore only CRTC reads;
          * we retain any writes in case that information proves useful later.
          *
          * Note that returning an undefined value now signals the Bus component to return whatever default value
@@ -7328,7 +7332,7 @@ Video.TOUCH = {
  * Why simulate a SPACE if the tap is in the middle third (center) of the screen?  Well, apparently
  * I didn't explain earlier that the WHOLE reason I originally added KEYGRID support (before it was
  * even called KEYGRID support) was to make the 1985 game "Rogue" (pcjs.org/apps/pcx86/1985/rogue)
- * more fun to play on an iPad, and space is a commonly required key.
+ * more fun to play on an iPad (the space-bar is a commonly required key).
  */
 Video.KEYGRID = [
     [Keyboard.SIMCODE.HOME, Keyboard.SIMCODE.UP,    Keyboard.SIMCODE.PGUP],

versions/pcx86/1.35.1/pcx86-uncompiled.js

@@ -9462,7 +9462,7 @@ class Bus extends Component {
             if (aNotify !== undefined) {
                 if (aNotify[0]) {
                     dataPort = aNotify[0](port, addrLIP);
-                    if (dataPort === undefined) {
+                    if (dataPort == null) {
                         dataPort = maskPort;
                     } else {
                         dataPort &= maskPort;
@@ -49588,10 +49588,6 @@ class Video extends Component {
         this.buildFonts();
 
         this.nMode = null;
-        this.iCellCursor = -1;  // initially, there is no visible cursor cell
-        this.cBlinks = -1;      // initially, blinking is not active
-        this.cBlinkVisible = 0; // no visible blinking characters (yet)
-
         this.setMode(this.nModeDefault);
 
         if (this.cardActive.addrBuffer && fRandomize) {
@@ -50119,6 +50115,14 @@ class Video extends Component {
                 }
             }
         }
+        if (!fRebuild) {
+            /*
+             * Perform some additional initialization common to both reset() and restore() sequences.
+             */
+            this.iCellCursor = -1;  // initially, there is no visible cursor cell
+            this.cBlinks = -1;      // initially, blinking is not active
+            this.cBlinkVisible = 0; // no visible blinking characters (yet)
+        }
         return fChanges;
     }
 
@@ -52821,7 +52825,7 @@ class Video extends Component {
          * The IBM VGA ROM makes some hardware determinations based on how the CRTC controller responds when
          * the IO_SELECT bit in the Miscellaneous Output Register is cleared; normally, that would mean ports
          * 0x3B? are decoded and ports 0x3D? are ignored.  We didn't used to bother ignoring them, but the
-         * VGA ROM's logic requires it, so now we also check fActive.  However, we ignore only CTRC reads;
+         * VGA ROM's logic requires it, so now we also check fActive.  However, we ignore only CRTC reads;
          * we retain any writes in case that information proves useful later.
          *
          * Note that returning an undefined value now signals the Bus component to return whatever default value
@@ -53750,7 +53754,7 @@ Video.TOUCH = {
  * Why simulate a SPACE if the tap is in the middle third (center) of the screen?  Well, apparently
  * I didn't explain earlier that the WHOLE reason I originally added KEYGRID support (before it was
  * even called KEYGRID support) was to make the 1985 game "Rogue" (pcjs.org/apps/pcx86/1985/rogue)
- * more fun to play on an iPad, and space is a commonly required key.
+ * more fun to play on an iPad (the space-bar is a commonly required key).
  */
 Video.KEYGRID = [
     [Keyboard.SIMCODE.HOME, Keyboard.SIMCODE.UP,    Keyboard.SIMCODE.PGUP],