v1.37.1: Fixed a CPU bug wherein resetting a running CPU could result in multiple runCPU() timeout handlers being created (there should never be more than one outstanding runCPU() setTimeout request); also modified the Keyboard component to use a CPU-driven timer instead of setTimeout() for keystroke injection, so that stopping/starting the CPU won't interfere with the injection process

modules/shared/bin/printf

@@ -0,0 +1,71 @@
+#!/usr/bin/env node
+/**
+ * @fileoverview Test the sprintf() function
+ * @author <a href="mailto:Jeff@pcjs.org">Jeff Parsons</a>
+ * @copyright © Jeff Parsons 2012-2017
+ * @suppress {missingProperties}
+ *
+ * This file is part of PCjs, a computer emulation software project at <http://pcjs.org/>.
+ *
+ * PCjs is free software: you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * PCjs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
+ * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with PCjs.  If not,
+ * see <http://www.gnu.org/licenses/gpl.html>.
+ *
+ * You are required to include the above copyright notice in every modified copy of this work
+ * and to display that copyright notice when the software starts running; see COPYRIGHT in
+ * <http://pcjs.org/modules/shared/lib/defines.js>.
+ *
+ * Some PCjs files also attempt to load external resource files, such as character-image files,
+ * ROM files, and disk image files. Those external resource files are not considered part of PCjs
+ * for purposes of the GNU General Public License, and the author does not claim any copyright
+ * as to their contents.
+ */
+
+"use strict";
+
+var repl = require("repl");
+var Defines = require("../lib/defines");
+var Str = require("../lib/strlib");
+
+/**
+ * printf(sFormat, sValue)
+ *
+ * @param {string} sFormat
+ * @param {number} sValue
+ * @return {boolean}
+ */
+function printf(sFormat, sValue)
+{
+    console.log('printf("' + sFormat + '", ' + sValue + "): '" + Str.sprintf(sFormat, +sValue) + "'");
+    return true;
+}
+
+/**
+ * onCommand(cmd, context, filename, callback)
+ *
+ * @param {string} cmd
+ * @param {Object} context
+ * @param {string} filename
+ * @param {function(Object|null, Object)} callback
+ */
+var onCommand = function (cmd, context, filename, callback)
+{
+    var result = false;
+    var match = cmd.match(/([^ ]*) *(.*?)\s*$/);
+    if (match && match[1]) result = printf(match[1], match[2]);
+    callback(null, result);
+};
+
+repl.start({
+    prompt: "printf> ",
+    input: process.stdin,
+    output: process.stdout,
+    eval: onCommand
+});

modules/shared/lib/strlib.js

@@ -599,6 +599,70 @@ class Str {
         return fPadLeft? (sPadding + s).slice(-cch) : (s + sPadding).slice(0, cch);
     }
 
+    /**
+     * sprintf(format, ...)
+     *
+     * Copied from the CCjs project (/ccjs/lib/stdio.js) and extended.  Far from complete let alone sprintf-compatible,
+     * but it's a start.
+     *
+     * @param {string} format
+     * @param {...} args
+     * @return {string}
+     */
+    static sprintf(format, ...args)
+    {
+        var parts = format.split(/%([-+ 0#]?)([0-9]*)(\.?)([0-9]*)([hlL]?)([A-Za-z%])/);
+        var buffer = "";
+        var partIndex = 0;
+        for (var i = 0; i < args.length; i++) {
+
+            var arg = args[i], d, s;
+            buffer += parts[partIndex++];
+            var flags = parts[partIndex];
+            var minimum = +parts[partIndex+1] || 0;
+            var precision = +parts[partIndex+3] || 0;
+            var conversion = parts[partIndex+5];
+
+            switch(conversion) {
+            case 'd':
+            case 'f':
+                d = Math.trunc(arg);
+                s = d + "";
+                if (precision) {
+                    minimum -= (precision + 1);
+                }
+                if (s.length < minimum) {
+                    if (flags == '0') {
+                        if (d < 0) minimum--;
+                        s = ("0000000000" + Math.abs(d)).slice(-minimum);
+                        if (d < 0) s = '-' + s;
+                    } else {
+                        s = ("          " + s).slice(-minimum);
+                    }
+                }
+                if (precision) {
+                    d = Math.trunc((arg - Math.trunc(arg)) * Math.pow(10, precision));
+                    s += '.' + ("0000000000" + Math.abs(d)).slice(-precision);
+                }
+                buffer += s;
+                break;
+            case 's':
+                buffer += arg;
+                break;
+            default:
+                /*
+                 * The supported ANSI C set of conversions: "dioxXucsfeEgGpn%"
+                 */
+                buffer += "(unrecognized printf conversion %" + conversion + ")";
+                break;
+            }
+
+            partIndex += 6;
+        }
+        buffer += parts[partIndex];
+        return buffer;
+    }
+
     /**
      * stripLeadingZeros(s, fPad)
      *