init code for 8800 simulator, with a simple temporary test code in index.html

2020-03-06 12:36:30 +08:00 · 2020-03-06 12:36:30 +08:00 · dd9c51125c
parent 00a6a5ccdd
commit dd9c51125c
2 changed files with 133 additions and 0 deletions
--- a/index.html
+++ b/index.html
@ -0,0 +1,29 @@
+<!doctype html>
+<html>
+  <head>
+  </head>
+  <body onload="test();">
+
+    <h1>test</h1>
+    <div id="dump"></div>
+
+    <script src="js/8080.js"></script>
+    <script src="js/sim8800.js"></script>
+    <script>
+     function test() {
+       var sim = new Sim8800(256, 100000);
+       var dumpElem = document.getElementById('dump');
+       sim.dumpMem(dumpElem);
+
+       var writeFunc = sim.getWriteByteCallback();
+       var readFunc = sim.getReadByteCallback();
+
+       var i = readFunc(256);
+       writeFunc(256, 16);
+       i = readFunc(256);
+
+       sim.dumpMem(dumpElem);
+     }
+    </script>
+  </body>
+</html>
--- a/js/sim8800.js
+++ b/js/sim8800.js
@ -0,0 +1,104 @@
+/**
+ *   Copyright 2020 wixette@gmail.com
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License");
+ *   you may not use this file except in compliance with the License.
+ *   You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ *
+ * @fileoverview Altair 8800 front panel simulator.
+ */
+
+
+/**
+ * The simulator.
+ */
+class Sim8800 {
+    /**
+     * @param {number} memSize The memory size, in bytes.
+     * @param {number} clockRate The clock rate.
+     */
+    constructor(memSize, clockRate) {
+        /** @type {number} */
+        this.clockRate = clockRate;
+        /** @type {Array<number>} */
+        this.mem = new Array(memSize);
+        this.initMem();
+    }
+
+    /**
+     * Returns the byteTo (write memory) callback.
+     * @return {function(number, number)}
+     */
+    getWriteByteCallback() {
+        var self = this;
+        return function(address, value) {
+            address = address % self.mem.length;
+            self.mem[address] = value;
+            window.console.log('writing byte @' + Sim8800.toHex(address, 8)
+                               + ' : ' + Sim8800.toHex(value, 2));
+        };
+    }
+
+    /**
+     * Returns the byteAt (read memory) callback.
+     * @return {function(number): number}
+     */
+    getReadByteCallback() {
+        var self = this;
+        return function(address) {
+            address = address % self.mem.length;
+            var value = self.mem[address];
+            window.console.log('reading byte @' + Sim8800.toHex(address, 8)
+                               + ' : ' + Sim8800.toHex(value, 2));
+            return value;
+        };
+    }
+
+    /**
+     * Formats a number to fixed length hex string.
+     * @param {number} n The number to be formatted.
+     * @param {number} len The output length, with leading zeros.
+     */
+    static toHex(n, len) {
+        var leadingZeros = (new Array(len)).fill('0').join('');
+        return (leadingZeros + n.toString(16)).substr(-len);
+    }
+
+    /**
+     * Fills the memory with random numbers.
+     */
+    initMem() {
+        for (let i = 0; i < this.mem.length; i++) {
+            this.mem[i] = Math.floor(Math.random() * 256);
+        }
+    }
+
+    /**
+     * Dumps the memory to HTML, for debugging or monitoring.
+     * @param {Element} containerElem The DOM element to hold the generated HTML.
+     */
+    dumpMem(containerElem) {
+        var sb = ['<pre>\n'];
+        for (let i = 0; i < this.mem.length; i += 16) {
+            sb.push(Sim8800.toHex(i, 4));
+            sb.push('  ');
+            for (let j = i;
+                 j < Math.min(this.mem.length, i + 16);
+                 j++) {
+                sb.push(Sim8800.toHex(this.mem[j], 2));
+                sb.push((j + 1) % 8 == 0 ? '  ' : ' ');
+            }
+            sb.push('\n');
+        }
+        sb.push('</pre>\n');
+        containerElem.innerHTML = sb.join('');
+    }
+};