Actually written in Assembler to it. You had to squeeze the entire code and the graphics to 16k (K, that is 1024 bytes!). Rendering the screen was directly poking values to the hardware. Great piece of hardware
That would have been a specific machine built around the Z80. The Z80 CPU has a 16-bit address bus and can handle 64K of memory. It has an 8-bit I/O bus, but it was common for Z80-based machines to use memory-mapped I/O like the 6502.
Two very common machines from the era were the ZX spectrum and the TRS-80. But there were dozens - Kaypro, Osborne, MSX, the Nintendo Gameboy... the Z80 was used in lots of machines. Chips based on the Z80 are still used in embedded systems today.
I built a retro-computer this year using a Z180, which is a Z80 (minus undocumented behaviours) core with a handful of useful peripherals built in. They're still actively manufactured and sold.
The Gameboy did not use the Z80. Gameboy CPU was derived from the 8080 with a smattering of Z80 instructions (very few in the big picture). However, the Sega Master System was a full on Z80.
Two very common machines from the era were the ZX spectrum and the TRS-80. But there were dozens - Kaypro, Osborne, MSX, the Nintendo Gameboy... the Z80 was used in lots of machines. Chips based on the Z80 are still used in embedded systems today.
I built a retro-computer this year using a Z180, which is a Z80 (minus undocumented behaviours) core with a handful of useful peripherals built in. They're still actively manufactured and sold.