Why? The 600 came with 2.05 IIRC, and that's a bit large to try to do by disks. With the 500, you could just use a workbench 1.2 disk (if it's a 1.3 ROM) and get away with that. There might be a few small compatibility issues, but for the most part, it would work. But again, why? There would be very few if any advantages.