Docs: Add an abandoned interval-timer-based refactor of the main CPU loop to dev notes

notes/2023-08-15--dev-notes.md

@@ -35,3 +35,18 @@ Ken Shirriff, [The 6502 overflow flag explained mathematically](https://www.righ
 - `30   ` - initial value for IP
 - `30-80` - free
 - `80-FF` - free, can be bank-switched
+
+## Looping using an interval timer
+
+    const loop = setInterval(async () => {
+      step = step + 1;
+      // Temporary limit as a lazy way to halt infinite loops:
+      if (CYCLE_LIMIT && (step > CYCLE_LIMIT)) {
+        console.log('SIMULATION HALTING - reached cycle limit');
+        clearInterval(loop);
+      }
+      if (!CPU.running) clearInterval(loop);
+      if (CPU.IP >= CPU.memory.length) clearInterval(loop);
+      stepCPU();
+      await logCPUState(debug);
+    }, frameRate);