diff --git a/src/cardiograph.js b/src/cardiograph.js
index e25c921..47d89b0 100755
--- a/src/cardiograph.js
+++ b/src/cardiograph.js
@@ -1,6 +1,9 @@
 #!/usr/bin/env node
 
+const fs = require('fs');
+
 const DBG = require('./dbg.js');
+const Opter = require('./opter/opter.js');
 const { num2hex, bool2bit } = require('./conversions.js');
 
 const CFG = require('./machine.config.js');
@@ -15,16 +18,25 @@ let cpu = new CPU(CFG.initialIP, CFG.defaultCycleLimit);
 main();
 
 async function main() {
-  const input = await readPipedStdin();
+  const opter = new Opter();
+  opter.addOption('-d', '--debug');
+  opter.addOption('-i', '--in', false, true, 1);
+  const opts = opter.parse(process.argv);
 
-  const debuggable = true; // FIXME - Get this as a command line flag instead
-  // if debuggable === true, the input is JSON {sourceInfo, machineCode}
+  const sourcecodeHasAnnotations = 'debug' in opts;
+  // if true, then the input is JSON {sourceInfo, machineCode}
   // otherwise, the input is a string of space-separated numbers
 
+  let input = null;
+  if ('in' in opts) { // Read from file
+    input = fs.readFileSync(opts.in[0], 'utf8');
+  } else { // Read from stdin
+    input = await readPipedStdin();
+  }
+
   let code = null;
   let sourceInfo = null;
-
-  if (!debuggable) {
+  if (!sourcecodeHasAnnotations) {
     code = new Uint8Array(input.split(' '));
   } else {
     const parsedInput = JSON.parse(input);
@@ -33,7 +45,7 @@ async function main() {
   }
 
   cpu.loadMemory(code);
-  if (debuggable) { cpu.loadSourceInfo(sourceInfo); }
+  if (sourcecodeHasAnnotations) { cpu.loadSourceInfo(sourceInfo); }
 
   cpu.onCycleEnd(tick);
   cpu.onCycleEnd(logCPUState);