Reference

• Z80N Instructions — The thirty extended opcodes, with their flags and cycle counts.
• Next Registers — The nextreg map, and the coupling between registers.
• I/O Ports — Port decode, read values and write side effects.
• Machine Timing — Frame geometry, interrupt position and memory contention.
• ULAplus — The 64-colour palette.
• Plus3DOS and NextBASIC Files — The +3DOS header and tokenised NextBASIC.