diff --git a/assets/disk0/inttest.js b/assets/disk0/inttest.js
new file mode 100644
index 0000000..4ddf188
--- /dev/null
+++ b/assets/disk0/inttest.js
@@ -0,0 +1 @@
+throw new InterruptedException("lol");
diff --git a/assets/disk0/tvdos/TVDOS.SYS b/assets/disk0/tvdos/TVDOS.SYS
index 21ff776..164e096 100644
--- a/assets/disk0/tvdos/TVDOS.SYS
+++ b/assets/disk0/tvdos/TVDOS.SYS
@@ -128,7 +128,18 @@ var GL = eval(filesystem.readAll("A"));
 // @param args arguments for the program, must be Array, and args[0] is always the name of the program, e.g.
 //        for command line 'echo foo bar', args[0] must be 'echo'
 var execApp = (cmdsrc, args) => {
-    var execAppPrg = eval("var _appStub=function(exec_args){\n"+cmdsrc+"\n};_appStub;"); // making 'exec_args' a app-level global
+    var execAppPrg = eval(
+`function InterruptedException(m){this.message=m;this.stack=(new Error()).stack;};` +
+`InterruptedException.prototype=Object.create(Error.prototype);` +
+`InterruptedException.prototype.name='InterruptedException';` +
+`InterruptedException.prototype.constructor=InterruptedException;` +
+`var _appStub=function(exec_args){${cmdsrc}
+};try {_appStub;}
+catch (e){
+    if (e instanceof InterruptedException) 'SIGTERM';
+    else 1;
+}`); // making 'exec_args' a app-level global
+
     return execAppPrg(args);
 }
 
diff --git a/assets/disk0/tvdos/bin/command.js b/assets/disk0/tvdos/bin/command.js
index 81c7957..6941892 100644
--- a/assets/disk0/tvdos/bin/command.js
+++ b/assets/disk0/tvdos/bin/command.js
@@ -380,13 +380,13 @@ shell.execute = function(line) {
                 sendLcdMsg(_G.shellProgramTitles[_G.shellProgramTitles.length - 1]);
                 //serial.println(_G.shellProgramTitles);
 
-                let ret = execApp(programCode, tokens)|0; // return value of undefined will cast into 0
+                let ret = execApp(programCode, tokens); // return value of undefined will cast into 0
 
                 _G.shellProgramTitles.pop();
                 sendLcdMsg(_G.shellProgramTitles[_G.shellProgramTitles.length - 1]);
                 //serial.println(_G.shellProgramTitles);
 
-                return ret;
+                return (ret == undefined) ? 0 : ret;
             }
         }
     }
@@ -457,13 +457,14 @@ if (goInteractive) {
                 try {
                     errorlevel = 0; // reset the number
                     errorlevel = shell.execute(cmdbuf);
-                    if (isNaN(errorlevel)) errorlevel = 2;
+                    //if (isNaN(errorlevel)) errorlevel = 2;
+                    serial.printerr(`errorlevel: ${errorlevel}`);
                 }
                 catch (e) {
                     printerrln("\n"+(e.stack || e));
-                    if (errorlevel === 0 || isNaN(errorlevel)) {
-                        errorlevel = 1; // generic failure
-                    }
+                    //if (errorlevel === 0 || isNaN(errorlevel)) {
+                    //    errorlevel = 1; // generic failure
+                    //}
                 }
                 finally {
                     if (cmdbuf.trim().length > 0)