#+TITLE: Terminology #+AUTHOR: Riyyi #+LANGUAGE: en #+OPTIONS: toc:nil GameBoy terminology. ** Terminology *** Hardware | Name | Modern equivalent | Description | |-----------------+-------------------+-------------------------------------------| | APU | Sound card | Audio Processing Unit | | PPU | GPU | Pixel Processing Unit | | Bootrom | BIOS | | | HRAM (High RAM) | CPU cache | Embedded memory inside the CPU, 127 bytes | | WRAM (Work RAM) | RAM | | *** Flags The Half Cary (H) flag differs between 8-bit or 16-bit operations. The 8-bit variant indicates carry for the lower 4 bits of the result, or overflow from bit 4 to bit 5. The 16-bit variant indicates carry for the lower 4 bits of the *second* byte of the result, or overflow from bit 12 to bit 13. *** Opcode | Name | Bits | Sign | Mnemonics | [[https://gbdev.io/gb-opcodes/optables/][1]] | [[https://rgbds.gbdev.io/docs/v0.5.2/gbz80.7/][2]] | [[https://gekkio.fi/files/gb-docs/gbctr.pdf][3]]/[[http://marc.rawer.de/Gameboy/Docs/GBCPUman.pdf][3]] | [[https://gbdev.io/pandocs/CPU_Instruction_Set.html][4]] | Description | Note | |-----------+------+----------+-----------+------+-----+------+-----+------------------------------+-------------------| | | | | | | | | | | | | immediate | 8 | unsigned | i8 | d8 | n8 | n | | Next byte in memory | | | immediate | 16 | unsigned | i16 | d16 | n16 | nn | | Next byte in memory | little-endian | | register | 8 | unsigned | r8 | | r8 | r | | Any of the registers | | | register | 16 | unsigned | r16 | | r16 | rr | | Any of the registers | little-endian | | address | 8 | unsigned | a8 | | | (n) | | Address at value | | | address | 16 | unsigned | a16 | a16 | n16 | (nn) | nn | Address at value | little-endian | | immediate | 8 | signed | s8 | r8 | e8 | e | dd | Next byte in memory | | | immediate | 8 | unsigned | io8 | (a8) | n16 | (n) | n | 0xff00 + next byte in memory | write to I/O-port | | condition | | | | NZ | cc | | f | Execute if condition met | | d = data \\ n = constant *** Variables | Name | Meaning | |--------+--------------------| | length | amount of elements | | size | amount of bytes | |--------+--------------------| | lhs | left hand side | | rhs | right hand side | ** References - https://gbdev.io/pandocs/Memory_Map.html - https://gbdev.io/pandocs/Specifications.html