@hoglet hosted another mini-meetup a few days ago. He’d recently acquired a Microprofessor Z80 trainer, which had not only a 2k monitor but also a 2k tinybasic, so we did the bare minimum of programming with that, using a hand-cut keyboard overlay. It’s seen here with his FPGA-based ICE project in the Z80 socket - this machine has an interesting single-step approach which counts instructions and fires an interrupt, so the ICE has to be very careful to appear always to be running instructions.
The monitor is very basic and the tinybasic is very tiny - just 66 variables and no arrays. The machine does have a cassette save and load though. Lots of docs here: