It's not exactly what you're asking, but a few years ago I revisited the Spectrum programming of my youth in an emulator using modern editors and assemblers etc

It's not exactly what you're asking, but a few years ago I revisited the Spectrum programming of my youth in an emulator using modern editors and assemblers etc outside the emulated hardware. The emulator could pause and trace all the memory locations live which made debugging great. It was a way easier, more fun and productive experience than doing it for real on an 8bit machine was back in the day.