Game Boy Command Overview; Foreword; Cpu Registers; Generally - Nintendo DMG-01 - Game Boy Console Manual

TM
Game Boy CPU Manual

3. Game Boy command overview

3.1. Foreword

Since books on the Z80 are getting harder & harder to
find, hopefully the information here might be helpful
to those trying to understand assembly language
specific to GameBoy.

3.2. CPU Registers

3.2.1. Generally

The GameBoy has instructions & registers similar to the
Intel 8080, Intel 8085, & Zilog Z80 microprocessors. It
has eight 8-bit registers A,B,C,D,E,F,H,L and two 16-
bit registers SP & PC:
Some instructions, however, allow you to use the
registers A,B,C,D,E,H, & L as 16-bit registers by
pairing them up in the following manner: AF,BC,DE, &
HL. The F register is indirectly accessible by the
by DP
3. Game Boy command overview
15..8 7..0
A F
B C
D E
H L
SP
PC
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