- Based on receiving output to port 254 via a tap in Z80free_Out()
- Done well enough to support BASIC programming (and Z80, no doubt)
- Damage mechanism is brutal, simply everything all the time
- Damage must be split into 4 regions, for both `_from` and `_upto`
- Eventually, this would make it a fully event-driven model
- The actual writing of pixels is already event-driven or lazy
- Current CPU use has risen to ~39% due to writing large regions