Write, assemble, load and debug Z80 machine code for the ZX Spectrum (48K/128K) and compatibles. Use this WHENEVER the user wants to write a Z80 assembly routine, a BASIC `USR` machine-code "wstawka", a fast plotter/sprite/scroller, an interrupt (IM2) handler, a keyboard/joystick reader, or anything that drives the Spectrum hardware directly (display file at 0x4000, attribute file at 0x5800, ULA/border/beeper via port 0xFE, contended memory timing). It explains the Z80 register set and flags, the instruction groups, the non-linear screen layout and its address maths, ROM entry points and system variables, and how to assemble with sjasmplus (preferred), pasmo or z88dk-z80a…
