Bug Squad is a 'Centipede' clone for the Commodore 64. It started as a BASIC program with machine code only for time-sensitive portions, and over time the BASIC scaffolding got replaced until it was all machine code. Unlike the PET there was no built-in monitor program, so I used a snippet of BASIC that took hex and wrote it to memory, or took memory and dumped it out as hex. The downside being that to this day when I see A9 XX, or 8D XX XX I can't help but read 'Load Accumulator Immediate', or 'Store Accumulator Absolute'.