golangemusIgnacio Sánchez Ginés

@drhelius

Emulator = legalROM = ilegal

Emulator ≠ Simulator

InterpreterLD A,(HL)SUB 1JR C,CONTINUECP BJR NZ,LOOP

Decode

Read

Exec

Binary Translation

TargetMachineCode

LD A,(HL)SUB 1JR C,CONTINUECP BJR NZ,LOOP

Dynamic Recompilation

Trans

Read

Exec

LD A,(HL)SUB 1JR C,CONTINUECP BJR NZ,LOOP

TargetMachineCode

CPUMEM

IO

Audio

Video

Input

CPU6502 Z80

Game Boy *Master SystemGame Gear

MSXZX Spectrum

NESAtari 2600Commodore 64

Apple 2Super NES 65816

CPU MEM8-bit

16-bit

0000

FFFF

0

65535

16KB

16KB

16KB

16KB

8DC4F3CD293D2144FF3E92BE20FDCD0C........

parameter

opcode opcodeopcode

parameter

Main Loopwhile true {

updateCPU() updateVideo() updateInput() updateAudio()

}

updateCPU() { opcode = fetchOpcode()runOpcode(opcode)

}

100 clks N clks

CPU

Video

Input

CPU4 MHz

MEM

Timer

Audio

Video

InputCart

Game Boy

CPU

H L

B C D E

SPPC

A F

16 bit 8 bit

Flags

0 0H C 0 0Z N1 05 4 3 27 6

16 KB ROM Bank 016 KB switchable ROM bank

8 KB Video RAM

8 KB switchable RAM bank8 KB internal RAM

Mirror 8 KB internal RAMSprite Memory (OAM)

EmptyIO PortsEmpty

Internal RAM

Interrupt Register

cartridge

FF4CFF80

FEA0

FF00

FFFF

FE00E000

C000A000

80004000

0000

cartridge

jj+1

X

N

i+1i

21

16 KB ROM Bank 0

16 KB switchable ROM bank

8000

4000

0000

Bank 0

Bank 1

Bank 2

Bank 3

Bank 4

...

fixed00000

04000

08000

0C000

10000

14000

switchable

Bank 4

ROMRAM

MBC

Visible160x144

HBlank

VBlank 1.08 ms

48.6 us

Demo Emulator

main

core

glfw

opengl

cpu

video

input

Workshop

go get -u github.com/drhelius/demo-emulator

cd $GOPATH/src/github.com/drhelius

go run main.go -rom workshop.rom