Original Notetaker files

Author: codefrau

README.md

@@ -9,6 +9,12 @@ which also includes links to a live version using this VM in the accompanying [S
 
 The [index.html][standalone] in this directory should give you a running version for testing, although the browser integration is incomplete (e.g. copy/paste or file management). Pull requests welcome!
 
+By default this runs an updated image with fixes. To quote from the [paper][paper]:
+
+> Smalltalk-78 was never really finished. It was completed to the point of demonstration on the few NoteTakers that were actually built, but the machines were difficult to use with their small screens and marginal performance, and it was not easy to capture changes and feed them back into new releases. Originally, the Xerox group wrote a Smalltalk-78 image from a running Smalltalk-76 system and this was then moved to the NoteTaker and tried. After several iterations, one image worked well enough for demos. While a number of fixes were made and stored on NoteTaker floppy disks, those are long gone and they were never folded back into the snapshot we have.
+
+If you feel adventurous, you can run the [original, unmodified image][original] as found on the disk pack, too.
+
 The full simulation environment including a graphical VM debugger is at the [Zoo's Smalltalk-78][full] page.
 There you can also try Adele Goldberg's SimKit and Alan Borning's Thinglab images running on this VM.
 
@@ -17,5 +23,6 @@ All of these work best in **Google Chrome**. Again, pull requests to improve bro
 [zoo]: https://smalltalkzoo.thechm.org/
 [full]: https://smalltalkzoo.thechm.org/HOPL-St78.html
 [standalone]: https://codefrau.github.io/Smalltalk78/
+[original]: https://codefrau.github.io/Smalltalk78/?image=notetaker
 [paper]: https://freudenbergs.de/vanessa/publications/Ingalls-2014-Smalltalk78.pdf
 [hopl]: https://smalltalkzoo.thechm.org/papers/EvolutionOfSmalltalk.pdf

Smalltalk78.js

@@ -368,10 +368,9 @@ function interpretLoop() {
     }
 }
 
-function runImage(buffer, imageName, canvas) {
-    window.localStorage['notetakerImageName'] = imageName;
-    var display = createDisplay(canvas),
-        image = St78.vm.Image.readFromBuffer(buffer, imageName);
+function runImage(image, canvas) {
+    window.localStorage['notetakerImageName'] = image.name;
+    var display = createDisplay(canvas);
     Smalltalk78.vm = new St78.vm.Interpreter(image, display);
     window.onbeforeunload = function() {
         return "Smalltalk78 is still running";
@@ -422,11 +421,29 @@ function loadImage(imageName, thenDo, elseDo) {
     }
 }
 
+// It's 2024. We can use modern JS now.
+async function runNotetakerFiles(url, imageName, canvas) {
+    // this is a special case for the original Notetaker files
+    // which have a different format than the images we write
+    const files = ["ObjectTable.nt", "ObjectSpace.nt"];
+    const responses = await Promise.all(files.map(file => fetch(url + "/" + file)));
+    const buffers = await Promise.all(responses.map(response => response.arrayBuffer()));
+    const objectTable = new Uint8Array(buffers[0]);
+    const objectSpace = new Uint8Array(buffers[1]);
+    const reader = new St78.vm.ObjectTableReader(objectTable, objectSpace, 49152);
+    const oopMap = reader.readObjects();
+    const image = new St78.vm.Image(oopMap, imageName, true);
+    runImage(image, canvas)
+}
+
 Smalltalk78.run = function(imageUrl, canvas) {
     // we let ?image=... override the image name (could be a full URL too)
     // otherwise the last-saved image name is used
     // the image then is loaded from browser storage unless ?fresh is given,
     // in which case it's always downloaded
+    // the special image name "notetaker" will load the original unmodified
+    // Notetaker files from ~1978, rather than the default image, which has
+    // been updated (implies ?fresh)
     var searchParams = new URLSearchParams(location.search);
     if (searchParams.get('image')) {
         imageUrl = searchParams.get('image');
@@ -436,7 +453,11 @@ Smalltalk78.run = function(imageUrl, canvas) {
     // now load the image, and if that fails, try to download it
     var url = new URL(imageUrl, document.location);
     var imageName = url.pathname.substring(url.pathname.lastIndexOf('/') + 1);
-    function run(buffer) { runImage(buffer, imageName, canvas); }
+    if (imageName == "notetaker") return runNotetakerFiles(url, imageName, canvas);
+    function run(buffer) {
+        var image = St78.vm.Image.readFromBuffer(buffer, imageName);
+        runImage(image, canvas);
+    }
     loadImage(imageName, run, function() {
         downloadImage(imageUrl, imageName, run, function() {
             alert("Failed to download: " + imageUrl);